Blue Screen of Death errors - how to avert your PC's death toll

What it is 

A blue screen error, also known as Blue Screen Of Death or BSOD or stop error, is shown when a problem occurs with processes running in kernel mode and Windows has to stop the system to prevent damages. A BSOD can be caused by problems with devices, drivers or a corrupted Windows installation. For this reason it's important to write down the type of stop error displayed on top and the specific number of the error displayed at the bottom of the screen (see pictures below).

 

Troubleshooting BSOD errors

 To troubleshoot these errors you need to:

• Search the Microsoft website for their number codes. If the error message lists a device driver or service as the reason for the problem, try to locate its program file using Windows Explorer; you can try to reinstall the device or program.
• After restarting, there could be a Windows error message box with useful information. At this point check Event Viewer and look for archived messages in the Action Center (for Vista, check Problem Reports And Solutions).
• Apply patches through Windows Update.
• Undo any recent changes to your system and, if you're not sure, use System Restore to revert the system to a state prior to the date when the problem has occurred.
• Use Memory Diagnostic Tool to check memory and check the hard drive for errors by using CHKDSK /r.

Some of the most common blue screen errors

1.   BAD_POOL_HEADER: it may occur for several reasons, such as corrupted Windows updates, bad memory or corrupted applications. When troubleshooting, start undoing the most recent change and see if this solves the problem (e.g. rollback a driver or uninstall a Windows update). In case of several recent changes, you may want to use System Restore. If this doesn't help, then memory could be bad and you should run a memory test. You can get more information from Event Viewer.

2.   NTFS_FILE_SYSTEM: the hard drive could be corrupted and you should run CHKDSK /r  from Command Prompt to check and fix errors.

3.   KERNEL_DATA_INPAGE_ERROR: Windows can’t read the paging file, which means is corrupted because of bad memory, a corrupted hard drive or a failing processor. You can try troubleshooting this error by rebuilding pagefile.sys from Command Prompt.

4.   UNEXPECTED_KERNEL_MODE_TRAP: it's most likely caused by bad memory and you can run Memory Diagnostics Utility to have a better picture of the situation.

5.   DIVIDE_BY_ZERO_ERROR: it can be caused by a malfunctioning application. 
IMPORTANT NOTE: Windows is setup by default to reboot automatically when a stop error occurs, so you might have to press F8 (SHIFT+F8 in Windows 8/10) to access the Advanced Menu Option and disable this option, so you can actually view the BSOD and write down the error code.

Wrap up  

Blue Screen Of Death errors are usually a bad symptom for a Windows system, because they may underlie major hardware or software issues, but they don't always mean the end of life for your PC. Sometimes they can be solved by changing specific software settings or restoring the default settings, while in other cases you may have to replace a faulty or damaged hardware component (hard drive, RAM, motherboard, etc.). 
In the best case scenarios they can be solved by rebooting the PC and/or accessing Safe Mode to correct some specific settings causing the problem.
For example, if you have an issue with virtual memory, you can try access Windows in Safe Mode and access the Virtual Memory configuration by right-clicking Computer and going to Advanced System Settings/Advanced/Virtual Memory/Change. Afterwards, select the default option, i.e. Automatically manage page size for all drives, as shown in the figure below, and reboot the PC. This can sometimes fix the problem, if it's due to a software misconfiguration and not to a hardware failure. 

Click to enlarge

Resources:

Microsoft official page
A complete list of BSOD errors