Saturday, August 07, 2010

Fixing Windows boot problems

Computers aren't perfect. Things can and will break down although we all prefer it to happen later rather than sooner.  Better yet don't happen at all.

Unfortunately, that's not possible. With proper maintenance you'll get more out of your machine but eventually it'll break down just as human beings grow older and eventually pass on.

Here I list a few of the Blue Screen of Death (BSoD) codes I've encountered with suggestions on how to go about resolving them. An exhaustive list is simply far too much for a single post so this will only have the BSoDs I've chanced on occasion.


This is a caused by a missing or corrupted ntdll.dll file. Restore a good copy using Recovery Console and you're good to go. Of course, there's reports scattered all over the Internet of other causes but I've not experienced those myself.


This happens when Windows can't gain access to the files on your hard disk which usually means a driver issue, failing hard disk, or filesystem corruption. If you've recently changed from IDE to a SATA hard disk, or even changed motherboard then that's your likely culprit there. You'll need to switch to IDE mode, or do a clean installation of Windows. Windows Vista/7 users won't have problems here. Otherwise, get the drive diagnostics software from the hard disk manufacturer and confirm that it's not a failing hard disk in need of replacement.

The last option would be a corrupted filesystem that you can fix with chkdsk /r from Recovery Console.


Similar to 0x0000007B, this is almost always a problem with the hard disk. Run a hard disk diagnostic, follow up with a chkdsk /r to fix up filesystem issues.

Stop 0x0000007E

This is an error with many possible causes. It can be caused by a failing hard disk, incompatible drivers, or even insufficient disk space. A BIOS update might even help.

Stop: c000021a {Fatal System Error}

I usually see this rather strange looking BSoD when Chinese Star is installed. It's a poorly made software that breaks when certain Windows security patches are applied. If this happens your only recourse is to do a repair installation, or a clean installation. I've never seen "Last Known Good Configuration" from the F8 menu fix this before and even a repair installation doesn't always work.

It might be a good idea to consider using the built-in Windows language bar, or install Google Pinyin instead. It's much better than Chinese Star and won't be giving you problems whenever you install some random Windows security update.

If you've never installed Chinese Star before but get this after removing malware on Windows then it's likely you have a missing/corrupted winlogon.exe or csrss.exe. Both are located in C:\Windows\system32. You can restore these from the originals on you Windows setup CD using Recovery Console, or even a Linux LiveCD.

Windows hangs after loading isapnp.sys

Windows displays a blank screen when booting normally and booting Safe Mode stops right after isapnp.sys is loaded. This is caused by a virus. Just use Recovery Console to remove any 0KB files in C:\Windows\system32\drivers and Windows should boot normally afterwards.

Related posts:

How to remove malware from Windows