So you have a Blue Screen (a.k.a Blue Screen of Death) with an error of 0x7d or 0x0000007d? The way to fix it is not THAT difficult. I have used this method with Windows XP and Vista. Windows 7 has a better recovery method that will do this for you automatically most of the time.

Get your Windows Install/Recovery DVD. Put DVD in computer and start/restart computer and boot to DVD. Sometimes you have to press a button to trigger the boot so read the options before it goes away (which can be quick). The most common buttons to trigger the boot menu are F8 and F12. Sometimes you have to press F2 or DELETE to modify the BIOS settings to set DVD Player as first bootable device and Hard Drive as second. The Hard Drive must always be in that list as either First or Second if the DVD-Rom is going to be First. After DVD boots, select Recovery option, enter Administrator password when Prompted (sometimes it is blank). Then follow the commands below adjusting if needed for your specific computer.

md tmp
copy c:\windows\system32\config\system c:\windows\tmp\system.bak
copy c:\windows\system32\config\software c:\windows\tmp\software.bak
copy c:\windows\system32\config\sam c:\windows\tmp\sam.bak
copy c:\windows\system32\config\security c:\windows\tmp\security.bak
copy c:\windows\system32\config\default c:\windows\tmp\default.bak

delete c:\windows\system32\config\system
delete c:\windows\system32\config\software
delete c:\windows\system32\config\sam
delete c:\windows\system32\config\security
delete c:\windows\system32\config\default

copy c:\windows\repair\system c:\windows\system32\config\system
copy c:\windows\repair\software c:\windows\system32\config\software
copy c:\windows\repair\sam c:\windows\system32\config\sam
copy c:\windows\repair\security c:\windows\system32\config\security
copy c:\windows\repair\default c:\windows\system32\config\default

Reboot, cross fingers, and hope all is well. The first 5 commands make sure you have a backup before you replace with files you do not know for sure if they will work. If they do not work then use the copy command again with the paths flipped around to undo what you did. There have been a few times that replacing the files one at a time did the trick. So if replacing all 5 don’t work then try replacing one at a time, rebooting and testing after each file.

I hope this helped fix your Blue Screen Of Death issue.