Fix Blue Screen of Death in Windows XP: Corrupted Registry

External factors that could cause a BSOD include viruses and malware. They can infect your computer, and then corrupt its drivers or system files. Thus, when you restart, or at the point that error will occur, the blue screen error will be displayed.

Internal factors include accidental changes in the installed software registry, damaged hardware components, or someone experimenting with Windows systems settings without really knowing what they are doing. Let's take these factors one at a time. 

First, let's look at ab accidental change in the installed software registry that has something to do with system files. This is due to faulty or buggy software installed on your computer. This is why it is highly recommended to install only trusted software/drivers or those signed by Microsoft. On the other hand, this problem can also be caused by someone changing settings in the system files, discussed below.

A damaged or faulty hardware component can improperly communicate with your operating system to send and receive data. Thus, while you're using the computer, a BSOD will appear. Common hardware components that can easily go down due to bugs include video cards and hard disks.

Finally, let's address the case of someone experimenting with Windows system settings without knowing what they're doing. This is common if you let anyone use your computer and log in as Admin. They might experiment with the settings in Windows XP and end up corrupting data. In this case, the next time you use the computer, you will notice that it suddenly displays a "blue screen" error, or even the worst thing that can happen: you won't be able to use Windows XP, so you can't log in or see your files anymore. 

This article attempts to correct any issue relating to a corrupt registry that is possibly causing the blue screen, WITHOUT the need to install third party software, re-install Windows or replace expensive hardware, which is very common.

A blue screen error looks hopeless; it's a frustrating experience to any Windows XP user. Most of the time, users will resort to drastic solutions which are not appropriate or necessary, such as:

• Buying expensive hardware components to replace the drive, video card and other parts without even going through the correct troubleshooting steps.
  
• Reinstalling Windows XP, a very common solution that requires the user to make a lot of sacrifices, such as losing saved files, useful documents and installed software.  
  
• Installing third party software in the hope of detecting the problem. Most of the time, this does not solve the the problem because such software is not perfect, and using such unfamiliar software incorrectly can even make the problem worse. 

Understanding this problem

In my years of experience using Windows XP, I noticed that one of the most frequent causes of blue screen error is a corrupted registry, which is the result of certain things being done to your computer as discussed on the previous page. The registry is a database used by Windows XP that acts as the "commander" of all Windows XP functions, even during start-up, and every piece of software that is installed on your computer. Even the most serious problem,  like being unable to log in to Windows XP and view files, is related to the registry.

Below is the troubleshooting chart that should be implemented regardless of whether the blue screen of death is caused by a corrupt registry or a hardware issue:

Based on the troubleshooting flowchart, it is only advisable to reinstall Windows XP when the blue screen still occurs after correcting possible corrupt registry entries. It is also advisable to go through hardware troubleshooting only if correcting the registry and reinstalling Windows XP won't solve the blue screen of death problem.

Back Up Important Files FIRST

Editing the registry is a very risky thing to do in your computer; a single mistake can lead to even bigger mistakes, which at worst will entirely prevent your computer from functioning from the start.

IMPORTANT: Therefore, to prevent any accidents, you MUST back up important files first.

There are two easy ways to back up files that depend on the extent of the problem currently occurring on your computer. Here they are:

First situation: Your computer won't boot properly and you cannot log in to Windows.

In this case, you need software that can access the NTFS partitions of your hard drive in order to copy files. One of the most effective approaches is to use the Linux Ubuntu Live CD. Here is a list of all the steps you should take to back up using this method:

• Connect an external hard disk in your computer. It's recommended that you use a USB-type external hard disk. 
  
• Place the Linux Ubuntu CD in the CD drive.
  
• Restart your computer to boot from the CD drive instead of the hard disk.
  
• The Linux Ubuntu CD will then start. Under the options, select: "Try Ubuntu without any change to your computer."
  
• Once you are able to boot with Linux, you can then see the hard drive files you should have seen before with Windows XP, as well as the USB external hard drive.
  
• Select the critical and important files, and then copy them to your USB external hard drive to provide some kind of backup.

If you need the detailed procedure, refer to this article. 

Second situation: You can boot to Windows

If you can successfully boot to Windows and the blue screen problem happens in between, after booting, then you can back up without any problem -- just use an external hard drive and do it quick. If, during the course of backing up, a blue screen occurs, use the first solution.

The Repair Concept

The concept of repairing a corrupted Windows registry is to effectively use the Windows SYSTEM RESTORE feature. Some Windows XP optimization sites recommend turning this feature off for optimization purposes, which is not good.

In the case of serious problems (like receiving a blue screen error), SYSTEM RESTORE is the only feature recommended by Microsoft to correct registry entries. So this means it should be turned on.

To check to see if it is turned on, go to Control Panel -> System -> System Restore. Make sure that "Turn off System Restore on all Drives" is unchecked.

Time after time, system restore will back up the Windows Registry and other application data automatically. So if Windows backed up the registry on August 24, 2009 and there are no problems encountered on that date or before that date, you can safely return/restore to this date if problems occur in the future (for example, if the blue screen problem first occurred on August 27, 2009)

Dealing with a corrupted registry is a two-step process. First, you must clean the registry. Use the Online Registry Cleaner provider by Microsoft.

After cleaning, observe the system for a couple of hours while using your computer. You can continue your observations for up to three straight days. If the blue screen reappears, you need to go to step two of this process.

Step two deals with the Windows Recovery Console. If you are unable to boot, then you cannot scan the registry online; proceed to "Windows Recovery Console" immediately.

Windows Recovery Console

The Windows Recovery Console is a DOS mode for repairing Windows XP files, particularly the registry. It is provided by the Windows XP installation CD. Make sure that you have this installation CD in order to use the Windows Recovery Console.

What we are going to do is use the Windows installation CD, restart the computer to boot from it, and then choose the "To repair a Windows XP installation using Recovery Console" option. After pressing "R," this will take you to the Windows Recovery Console. See the sample screen shot below of the Windows installation setup menu to the Windows Recovery Console.

If it asks for any administrator password, which is always the case, make sure you remember your Windows login password and use it for authentication purposes.

Here are some precautions to keep in mind when working with the Windows Recovery Console:

1. Type commands exactly as they appear in this tutorial -- lowercase to lower case, upper case to uppercase. Although Windows is not case sensitive, unlike UNIX or Linux, obeying commands as they appear is a good practice.

2. Use only a single space if there is spacing between commands. Do not use a double space.

3. Always review the commands very carefully before pressing the "Enter" key. Carelessness can cause a lot of problems.

Part two of this tutorial will give you the detailed procedure for the recovery console commands when you are ready.