Nuclear Power Generation in Singapore

5 November 2008

IntroductionSingapore is a small country state. It has only about 700 sq. km of land area. It is in close proximity to Indonesia and Malaysia who are always sensitive to any development in its neighbours. The building of a nuclear plant on land or at sea will be out of the question; however, there is a good chance that we can build a nuclear plant in a rock cavern, deep inside a piece of large rock located underground.

What is a Cavern?Cavern is just an empty space in a piece of rock or some solid rock materials. Three quarters of Singapore is presently sitting on pieces of big granite rock. There are also rocks of different structures and materials underneath Singapore. Some rocks are so big that one can build swimming pools or warehouses or even an Olympic Stadium in them. They can be used to house many facilities. A nuclear electricity generating plant can be one of them.

Presently, Singapore has an ammunition storage cavern somewhere underneath Bukit Timah hill. It will soon have oil storage caverns in Jurong Island. These caverns are large enough to store a few warehouses of ammunition and also storage tanks bigger that those we have seen presently on the Jurong Island.

an inside view of oil storage cavern

Why Cavern ?
1. Safety and security

• It is not exposed to military attack from the air
• It is not easily accessible because it would be rather hard to drill another access inside a rock located underground; hence, it is easy to keep facilities away from suicide bombers or the enemies.
• It is self contained. It can be built such that it will withstand and contain any nuclear disaster. There would be no need to remove any nuclear fuel or assemblies or debris. Monitoring would be minimal.

2. Storage and Transport of materials

• Caverns are good for storage of nuclear fuel. Spent or used fuel if any need not have to leave the caverns. Such fuel can be stored and sealed in other caverns forever with minimum effort and maximum security. No radioactive materials would need to be re-handled on the surface.

4. Waste and decommissioning

• When the reactor reaches the end of its useful life, the whole facility could be sealed, complete with the spent fuel. This will avoid the many problems of handling and re-handling of the nuclear waste and the decommissioning of nuclear facilities. The sealed cavern will need only minimal remote monitoring until it is ready for safer disposal.

5. Environmental impacts

• The nuclear plant can be designed to have no serious impact to the environment above ground. The vulnerable materials will be located inside the caverns. The use of the surface footprint would be limited to the accesses for the cavern, the electric power lines, the secondary cooling and other non-radioactive secondary circuits.

Example Overseas
1. Switzerland

• The country, one of the Europe's smallest (but still 50 times larger than Singapore), began its experiment with nuclear energy in 1957. Now, it has 5 nuclear plants supplying 40% of the electricity generation.
• They have a nuclear reactor constructed in 1962 located inside a rock cavern but it was decommissioned in 1969 due to an accident. It is recommended that Singapore understudies these developments in Switzerland.

2. Other Countries
Norway, Sweden and some other countries has constructed power plants in caverns. But all of these are not nuclear plants.
3. Words from the Experts
Jan A Rygh, a former director of a consulting company responsible for the overall planning of the Gjøvik Rock Cavern for the Olympic Stadium said that "we can easily create caverns big enough to put nuclear reactors .. and we would never experience another Chernobyl"
Problem and Concerns
1. Water seepage

• Water seepage can be a problem for caverns as no wall sealants will be permanent forever. The advent of membrane and the rock-engineering technology for sealing and draining would help. However, caverns can always be pressurized just like a balloon so that equal pressure will keep the water away. A well designed facility would need no real water pumping facilities that would otherwise required to contaminate the surface and environment.

2. Protest from Neighbours and Citizens

• Our neighbour and Citizens will protest. They will be very fearful of "what if". There should be efforts spent to educate them.

3. Danger of a total collapse

• The careful selection of a piece of rock to construct the nuclear plant is very important to ensure its success. Singapore has very good granite rocks underneath. We should be able to construct a good cavern that can withstand the catastrophic failure of a nuclear plant. We could always select a piece of good rock underneath the sea bed.
• There was no report of a total collapse of caverns in operation although there were reports about collapse of underground tunnels during the construction stage. The construction of space in cavern and underground tunnels are totally different in nature. The more than 30 times construction cost difference between them could give some prospective although the former involves taking out solid rock materials and the latter involves removing of the soft earth materials that will normally settle in time.

4. How deep? Will it affect Shipping?

• In Sweden, nuclear fuel are stored at about 30 metres below sea level. They have plans to store spent fuel finally 500 metres below. If the nuclear cavern is to be located under the sea bed, it should not have affected the shipping lanes as the seabeds are only of depths around 20 metres.

5. Will the Switzerland Failure Repeat?
The Swiss failure was due a burst in one of the pressure tubes, causing the reactor to malfunction. It is not quite related to the use of cavern for nuclear operation. More than 30 years have since passed, the advent of technology must have a solution to prevent a recurrence. This is a good example where Singapore could learn much from the Swiss before embarking a similar project.
6. Will the Cavern Be Able to Withstand Nuclear Blast?
There was no report of any nuclear test carried out using caverns although there were underground tests carried out as shown in this video. The blast at Chernobyl of Russia was said to be 50 Kilotons or 2.5 bigger than the 20 Kilotons shown in the video. But the following report indicated that underground nuclear test of more than 1 megaton had been carried out in the US. It is believed that caverns can be made to contain the nuclear catastrophic failures.
Other Alternatives
Other possible alternative is to construct a nuclear plant on floating platforms and float it 100 km away in Pacific Ocean. But this idea may be too risky as a nuclear power station is not only expensive with long submarine cables but also subject to security risk and many other legalities with Law of the Sea.
Conclusion
Singapore is a small nation that has no natural resource. It depends solely on fossil fuel for its electricity generation. It has no other alternative energies that can be harnessed in big quantities to alleviate the shortage of electricity supply. It will have to resort to building more and more fossil fuel plants in the future until it can find an alternative. Nuclear Power Plant built inside a cavern can be one of such an alternatives. The Government should spend efforts not only to carry out research and development work but also to educate its neighbours.

Construction work inside a rock cavern

Related Articles
1. Creative use of underground space
2. Sweden's Nuclear Plant with underground storage facility
3. Switzerland’s first nuclear plant decommissioned
4. Underground Nuclear Explosion Tests
5 Mini Nuclear Power Plant for Singapore

Is There X'mas Rally This Year?

30 October 2008

Many people expected a X'mas rally in stock market during the end of the year. Is there going to be one this year?

What is the chance?
If the past record or history is of any guide at all, there is a 5:2 chance that one would get a X'mas rally every year. But this year is quite different. It is a US election year and we have a global credit crisis and a global recession in our hands. But there is still a chance.

The X'mas Rally Years
Take DOW as an example. We have 53 good years for the past 90 years. DOW rallied through from 1 November right up to 24 December. For these good years shown attached, DOW gained more than 12%* in 1928, just before the Great Depression in 1929. DOW gained the least with only 0.12% in 1945, almost at the end of Second World War. The average gain stood at 4.2%. Most of the US Presidential Election year gave DOW the X'mas rally.

Note: * gain/loss compared to 1 Nov for the year. Same for the rest in this article

Doubleclick for enlarge view

The Bad Years
There are 7 bad years in DOW's 90-year history where there is no X'mas rally at all. DOW just fell straight from 1 November right through to 24 December. There was a nasty fall of 14% in 1973, when we had an oil spike triggering a World recession. The Black Monday on 1987 was not as bad though it had a fall of about 0.72%. The average was -4.6%.

Doubleclick for enlarged view

19 Half Cooked X'mas Rallies
There were altogether 19 X'mas rallies that started sometime near 1 November but fell short of running through to the X'mas day. Many of these were during US Presidential Election years where DOW gained more than 1.8%. There was the Dot.Com bubble year of 2000 where DOW rallied for 8 days. The Asian Financial Crisis and the Great Depression prevented DOW from rallying but they could still achieve a maximum gain of more than 1.4%. The most impressive gain was just after the Great Depression where DOW gained 12%. The Asian Financial Crisis did not dampen the spirit when DOW rallied and gained 6% on 5 December 1997.

Doubleclick for enlarged view

What are our Chances this year?
Judging from DOW's past performance, there is not a very good chance that the market will rally from 1 November right through to 24 December this year. However, there might be a chance that market will rally to a higher level mid way and form another half-cooked X'mas rally this year.

1997 and 2008 Stock Market

Introduction
Many claimed that the present stock market, affected by the America's credit crisis, looked more and more similar to the stock market during Asian Financial Crisis in 1997/1998.

The Asian Financial Crisis
The Asian Financial Crisis started sometime in late 1996 and the market recovered only in 1998. The market reclaimed its lost ground only in l Jan 2000, or about 3 years later. Then STI dropped from a high of 2,456 on 2 Sept 1996 to a low of 1,650 on 4 Sept 1998. That was about 800 points or 67% over a period of exactly 2 years. In between, STI saw a "dead cat bounce" of about 430 points or 35% from 1,245 on 16 Jan 1998 to 1,675 on 20 March 1998. This dead cat bounce lasted 2 months.



The 2008 Financial Crisis
The present financial crisis started from America. A bubble was formed in the US home sale market. It started to burst in mid 2007. Then a few hedge funds involved in the subprime home loan got into financial trouble in July 2007. This credit crisis grew bigger and bigger. First, a few smaller US banks gone bankrupt and finally, it affected larger banks like Bear Sterns, Freddie Mac, Fannie Mae and Lehman Brothers. Even AIG, one of the World's largest insurance company, was not spared. The crisis spread across the Globe. US Government cut interest rates and came up with more than US$1,000 billions of various financial packages to rescue the US economy.

During this crisis, DOW dropped from a high of 14,000 in Oct 2007 to a low of 8,145 on 27 Oct 2008. It lost a total of about 6,000 points or about 46% over a period of about 1 year. STI shed about 2,300 points from the high of about 3,900 to the present 1,600. This is a loss of about 60%, 14% more than DOW.


Are The Two Crisis Similar?
The Asian Financial Crisis and the US Credit Crisis are all connected to financial matters. There appears to have some similarity here. If we were to superimpose both time charts, they look something like this:


Has the Market Hit the Bottom?
Whether the market has hit its bottom or are there still more downsides to come, one will have to wait for Mr. Market to decide. The Asian Financial Crisis then was not as widely spread as the present US Credit Crisis. One would have to wait patiently to see the effectiveness of the rescue efforts put in by the various World's Central Banks.
The stock market could be taking a breather right now; but it may continue to dip if the rescue efforts put in by the various Governments were found not to be effective.


Related Articles
1. Bear Flag in Our Backyard 5 Sept 2008
2. Why STI Was Falling More than HSI, Shanghai and other Indexes? 4 Sept 2008

Power Savers. Do They Really Save Electricity Bills?

29 October 2008

Introduction
Electricity rate has gone sky high. Many will try to save electricity bills by trying out the installation of energy saving devices. Now, there are Power Savers available in the market. Do they really save electricity bills?

What are these Power Saver?
There are many different types of power savers in the market. Some are floor mounted, others are just small appliances with a 3 pin plug. All claimed to have saved electricity energy; some claimed to save up to 35%. This article will examine if they will really save your electricity bill.






The Salesman's Pitch
In the sale booth, the salesman can demonstrate to you that the Energy Saver can save energy.

Doesn't that Saves Energy?
What the salesman demonstrated is that by installing the Power Saver, the electric current is reduced. But that does not necessary mean that your monthly electricity bills will be reduced.

Why?
First, let us find out what are really inside these Power Savers. If one were to strip open the casing, one will find small electric capacitors.


What are these Electric Capacitors?
These are electronic components we often find in electronic appliances such as in Televisions. They may cost around $ 2 or $ 3 each. They are often used to smoothen electrical circuits to get rid of spikes. They can store up electricity energy just like our car batteries. In the application of Power Saver, the capacitors serve to correct the power factor of an electric appliance but they correct only the reactive and not the active power usage of an appliance.

What is Power Factor?
Power factor is a jargon used in electric and electronic power industries. It is nothing but a term defining the relationship between the active and reactive power of an alternative current or electric waves. Power factor is often referred to as the mathematical "cosine" of the angle between the active and the reactive power. It is one of measurements for the quality of the power supply system.

What are Active and Reactive Powers?Our electricity supplies active as well as reactive power to our homes. In simple layman term, the active power (measured in KW) is for us to produce work or heat whereas reactive power (measured in KVR) is related more to energy storage part of a system. For example, an appliance having pure resistances, such as electric heaters or irons, uses only the active power whereas an electric motor will use both the active power as well as the reactive power.

KWh Meters
By name, KWh meters measures only the active power (KW) of the electricity usage. The meters are constructed such that it ignores the reactive power usage. As Power Saver corrects only the reactive power, it does not save electricity bill directly.

Isn't the Reduction in Electric Current reduces KWh Meter Reading?
The ordinary home KWh meters are of electromechanical type. Each meter has 2 coils, a current and a voltage coil. They are arranged with 90 degree phase shift to always measure the active power usage of the electricity. Depending on the meter construction, many are affected only by the active power used by the network but the power factor of the network does have some effects on the meter reading.
In the case where the current drawn does affect the KWH meter reading, it shall be noted that most home appliances are either of resistive load or already installed with power factor correction capacitors in order to comply to the manufacturing specification. Therefore, additional capacitors provided by Power Saver will not serve much purpose. On the other hand, an over correction with more than enough capacitors may increase the current drawn.

It is therefore advisable not to install the Power Saver unless one is sure that the electric appliances to be used do not have the required capacitors already installed. Even then, the electricity bill saving may be minimal except for some heavy appliances such as air conditioners, where some users of Power Saver claimed to have saved some electricity cost.

DOW Jumped Almost 11%

29 October 2008

DOW jumped almost 10.9% last night, gaining about 890 points and lifted DOW from 8,175 to close at 9,065. This was the 2nd largest gain in the month. The last one was on 13 October 2008, just about 2 weeks ago. Then, DOW jumped 936 points or 11% to lift DOW to 9,387 from 8,451.
With such strong lift in DOW, does it mean that DOW has a total reversal?

Going through the above table, the matching days that DOW has made a gain of 10% or more are mostly done during the Great Depression period from 1929 to 1933.
The last time that DOW made similar gain was in October 1987, during the Black Friday/Monday. Then DOW gained about 10% on 21 October 1987 to compensate for the loss it had made on 19 October 1987, the Black Monday.
After that, DOW tanked for another 2 months. It then took off slowly over next 12 years and pushed its index up 5,000 points from 7.000 to 12,000, until the DOT.com bubble burst in year 2000.

(doubleclick to enlarge image)

Is this the wildest swing in HSI's History?

28 Oct 2008

Hang Seng plunged 1,600 points or 12.7% yesterday; it recovered 1,580 points or 14.3% today. Hang Seng went through a swing of about 3,000 points or 28% in the 2 days. Is this the wildest swing of Hang Seng's history? Is this an indication that Hang Seng has made a reversal?



According to record, Hang Seng made a similar swing during October 1997, the Asian Financial Crisis. On 28 October 1997, Hang Seng shed about 14% or 1,400 points to end the day at 9,060 points. The next day, on 29 October 1997, Hang Seng recovered 18.8% or 1,700 points as shown in the attached table.


A 3-year bull run pushed Hang Seng up about 10,000 points from 7,000 points in January 1995 to near 17,000 in August 1997. Then came the Asian Financial Crisis. This brought Hang Seng down to earth and made Hang Seng lost all the 10,000 points over next 12 months.
The October 1997 swing was then the largest swing since 1987. However, that swing did not manage to cause Hang Seng to make a total recovery. Hang Seng tanked for about 5 months after that and went down subsequently to recover in August 1998.

Is HSI's Fall of 12.7% the Highest in History?

27 October 2008

Hang Seng fell 12.7% or 1,600 points today in a volatile trade; it was down 15.4% for a brief moment with an intraday swing of about 2,000 points. It opened 12,373 and closed 11,015 just above a major support. In the morning trade, it went up to 12,737 but lost all its gain in the afternoon after Nikkei posted a 6% lost in the afternoon trade. The unwinding of Yen carry trade was said to be the cause.

According to the record, the last time Hang Seng closed 13% down was on 28 Oct 1997, during the Asia Financial Crisis. Then Hang Seng lost 14% to close at 9,060 although it opened about 600 points higher at 9,649.

The largest fall in the Hang Seng's history has to be the trade on 26 Oct 1987, exactly one week after the Black Monday on 19 Oct 1987. Then Hang Seng lost about 33% or 1,121 points.
It was reported that a 4-year bull run took Hang Seng to a record high of 3,968 points on 1 October 1987. On 16 October 1987, the Black Friday, global markets crashed. On the following Black Monday, 9 October 1987, Hang Seng shed 420 points to close at 3,362. This prompted the HK Exchange to suspend trading for the rest of the week to cool the market. When market resumed trading on 26 October, the following Monday, Hang Seng plunged 33 per cent on that single day.
With a fall of 1,600 points, Hang Seng slumped more than 65% from its peak of 31,958.41 in October 2007. This fall was more serious than the 62% fall experienced in the Asia Financial Crisis in 1997. On the other hand, Nikkie ended at lowest in 26 years with 7,162.

Replacing the Hard Disk

21 October 2008

After having scanned the harddisk using CHKDSK, the computer showed multiple error messages of “CHKDSK is performing additional checking or recovery…”. After having booted up the computer to backup the files, one received error messages.

What Could Have Gone Wrong?CHKDSK could have found bad sectors in the hard disk and making attempts to recover the bad sectors. This process usually takes less than 30 minutes. If the process takes hours with more than 20 error messages, one might have a faulty harddisk.

What should I do Next?
Back up as many files as possible. There might still be a chance that one could recover all the files if one can still boot up the computer. If one could not boot up the computer, try to repair the master boot sectors and the boot files. If the computer failed to start up after this, go and seek other solutions. One of the solution is to isolate the faulty section of the harddisk; the other solution is to repalce the harddisk. This article will describe the latter.

What do I need?
a) A copy of the XP installation disk
b) Another good harddisk of similar or bigger capacity

Why Not Use Existing Harddrive?
Unless one is sure about the condition of the harddisk, it is advisable to backup the files into another harddisk. Not only the existing harddisk might not have the necessary capacity, but also, the backing up operation might cause more damages to the harddisk.


Step by Step
1. Hooking up the new harddisk

• Switch off the computer and hook up the new harddisk as a slave drive
• Start up the computer and boot up the computer as usual
• Mount the new harddisk using available software such as Disk Manager or Partition Magic and Format the new harddisk

Mount the new harddisk with 2 partitions; one of them preferably with large enough capacity and formatted with NTFS system. This is because the normal FAT32 system has a limited capacity of 4 GB using the XP’s backup program.
2. Backing up the System/Program
If one has not backup the system/program before, should start to do so now. Back up as many programs as you can with priority giving to the following files
a) System state. This will restore your computer to its original condition
b) Important data, such as stock data, JPG, photos
c) Hard to get programs in “Program file”
d) One should also backup the necessary windows' drivers as one would have to install a new copy of the XP system on the new harddisk. This program can be used to extract drivers on the existing XP operating system.

Tips:

• Try to backup directory by directory. If there are error message, then select to backup sub-directory by sub-directory or file by file.
• Some program stores information in program/common file folder as well as in document and setting folder. When in doubt, try to backup as many files/directories as possible.
• Place the backup files in the new hard disk.
• If the backup file size is more than 4 GB, store the file in a NTFS partition
• Select to verify the data whenever possible.
• A lot to time and patient

3. Restoring the System/Program

• With the computer switched off, dismount the old harddisk and hook the new harddisk as the master drive.
• Reboot using XP installation disk
• Install new XP operating system in the new harddisk. Use the same username as the old copy of XP system when ask to create one

If everything is fine, restore all the backup files, one by one, starting in reverse sequent (though not important) as stated in

Why Not all the Menu Icons were shown?The restore should reinstate the computer to its original condition. If one has problem with missing icons in the menu, this could probably due to:

a) The username during XP installation is not the same as those in the old harddisk or the backup files
Check if there are more than one username folders in the “Documents and Settings” of the C: drive. Find the original username folder and check the sub folder , “C:\Documents and Settings\UserName\Desktop “ (username= your username) to see if it contains the menu icons that you have expected; if so, copy all the files/directories in this desktop folder over to the default username folder.

b) Some programs were not backed up properly
The programs or part of the program component could be missing.


Can One Re-Use the Old Harddisk?If one can boot up the computer, probably the damage in the hard disk are not as serious. If one want to reuse this faulty harddisk, one should

a) Try to re-run the CHKDSK again just to make sure that it has cleared all the bad sectors;
b) Clean the harddisk using the clean manager of XP system;
c) Defrag the disk, if possible in SAFEMODE

If everything else failed, one could always revive the harddisk .

Related Articles
1. How to Revive Faulty Hard Disk
1. Repair Damage Master Boot Record & Boot Sectors

How To Restart After Computer Hangs

17 October 2008

IntroductionThe computer just hanged. This article will try to offer some help step by step.

What can be wrong?
Restart the computer. If one can hear a soft and short beep sound, most likely the computer's hardware is working fine. The master boot record or boot files or the Registry of the XP's operating system may be corrupted.

What are the Usual Ways?
Usually, users will re-install the complete XP system. Some will choose to reformat the hard disk. One would lose all the personal documents, program files and other 3rd party programs. This article will describe a method that will not only save time for the restoration but also avoid having to reinstall all other programs.

What's Required?
a) A good working hard disk;
b) XP installation disk

How to?
Step 1 Suspect Faulty Master Boot Record or the Boot Files Follow the instructions in this article to repair the master boot record and the boot files and restart the computer. If the computer still hangs, then

Step 2 Suspect Faulty RegistryCopy the 5 files, namely: system, security, software, sam and default files from the “repair” sub folder to “config” sub folder in Windows and restart the computer to enter the safe mode. This Microsoft site gives the detailed instructions.

Thereafter:

a) If you have a Registry Backup copyFollowing this article to restore the Registry files from the backup copy and restart

b) If you do not have a Registry Backup Copy
Continue to follow the instructions given by Microsoft and restore the 5 files from a special “System Volume Information” folder. This folder is normally hidden from view. The system files are stored in this special folder when XP's System Restore is working. Note that the files in the folder may contain viruses as System Restore does not check for viruses when it stores the files.

Related articles
1. How to Restore Corrupted Registry
2. How to backup and restore Registry files
3, How to repair faulty Master Boot Record and Boot files

Back Up XP Registry and Boot Files

17 October 2008
Introduction
Viruses often attack the Registry of the computer’s operating system. After that, the viruses would be loaded to take control when the user starts the computer. This article will describe how we can back up a copy of the Registry and have it restored at a later date.

What is Registry and How Viruses Can attack it ?
Registry is a place where XP keeps all the information about the computer's hardware and software. It is being used by all the parties including 3rd party hardware and software. For example, if a new program has just been installed or files added, the Registry will be updated. Therefore, the Registry is the one place where it is most vulnerable to virus attacks. It is often difficult to get rid of them; sometimes, they may modify the Registry, making computers going hire-wired.
Viruses can be loaded into the Registry when we browse the Internet or when we run a program.
We can always restore the computer back to its earlier saved state if we have a backup copy.

How to Backup the Registry?
There are 3 methods:

Method 1: Using the System RestoreThis is part of the XP built-in program and can be set to save a copy of the Registry automatically or as and when required. Read this article.

Method 2: Backing up the whole of the Registry
Do this often manually or whenever we make some changes to the computer.

• Click Start, and then click Run. One will reach the following screen.
• In the drop down box, type "regedit"(without quotes), and then click OK

• In the next screen, select “My Computer” and in the File menu, click Export.

• In the "Save in" box, select a location where you want to save the Registry
• In the "File name" box, type a file name, and then click Save.

Note
1. This file will have an extension of ".reg" and is at least 5 Mbytes.
2. Make sure the computer is cleaned of viruses before saving.
3. Use separate file name each time as the copy of Registry to be saved could contain viruses.
4. Save this file in another hard drive or thumb drive or a RW CD ROM
Method 3: Backing up the System state
XP operating system has a built-in function called “Backup” in the System Tools folder. One can back up not only the whole registry but also the boot files in the Windows’ system 32 folder and the COM+ Class Registration Database.

• In the main Window, click Start, then in the All program/Accessories/System Tool folder, start the Backup program and follow the instructions, one should reach this screen

• Browse and select where the backup file should be installed and give the backup file a file name. Remember to use different file names if necessary. Click Next and one should reach the following screen.

• Select "Let me choose what to backup" and click Next to reach the following screen.

• Now, expand My Computer folder and then click the tick box next to "System State" folder as shown and click Next
• Select Advance button and after that, select "Normal" in dropdown box. Click next and one would reach the following screen to select the verification of file after backup. Tick that verification box and then Next. The computer will do the rest of job.
  
  
  Note
  1. One would need a free disk space of about 600 MB.
  2. Make sure the computer is cleaned of viruses before saving
  3. Store the backup file in a thumbdrive or RW CD or another harddisk so that it can be read and the backup file restored in case of harddisk failures.
  4. The backup file has a maximum limit of 4 GB for hard disk with FAT32 system rather than NTFS system. Check your system here.
  5. BACKUP is not installed by default in Windows XP Home Edition. Install it using the instructions available at: Q302894. A copy of Backup program can be downloaded here. Restoring the backup files
  To restore any Registry, always try to boot into the SAFE Mode. This will start the computer with minimum numbers of file and prevent viruses from loading.
  To boot into SAFE Mode, hit F8 continuously after the 1st welcome screen when one boots up the computer.
  When one is in the SAFE mode screen, might as well try if one could start the computer using the option "using Last Known Good Configuration".
  Method 1: Using System RestoreRefer to this article
  Method 2: Restore the whole of the Registry
  Go to the directory or the folder where the registry file was stored. Double click that file. The following screen will appear. Click OK
  
  Method 3: Restore the System state
  
  • Following Step 1 of method 3 in the backup section above, then choose "restore files and settings" instead, one should reach the following screen.
  
  
  • Browse through to the directory of the backup file and doubleclick the file, a new screen should show the folder "System State".
  • Tick the box to select file to restore and click Next. Click advance in the next screen. Change the default setting if necessary.
  Which of the 3 Methods is the Best?
  Method 3 appears to be the best; however, there were reports that it may not be compatible with some 3rd party software and may not restore everything in full. Sometime, it prompted users for CD keys etc after the restore.
  Method 2 is neat as it restores everything in full but it does not back up the boot file and Com+ file
  Method 1 is often the target of viruses. Very often, it would automatically save a copy of Registry complete with viruses. Some experts therefore recommended to de-activate the auto-saving function. To de-activate this function, just click start and the run in the main Windows and in the dropdown box, enter "sysdm.cpl" (without quotes). Then in the System Properties window, select the System Restore tab to untick box to turn off the system restore function.
  It is good to use all the 3 methods.

Related Articles
1. How To Restart After Computer Hangs