Question : Windows XP - BSOD STOP: C000021a The windows logon process terminated unexpectedly with a status of 0x00000005 (0x00000000 0x00000000)

Hi,
I have a Dell OptiPlex 755 desktop, running Windows XP SP3. It has been running fine for the past 2 years, and booted OK yesterday. However, today when booting up, it is giving a Blue Screen of Death (BSOD) just after it performs the 'Applying Computer Settings' screen. The error is:

STOP: C000021a {Fatal System Error} The windows logon process terminated unexpectedly with a status of 0x00000005 (0x00000000 0x00000000).

I have looked around, but can't find anything definitivate that suggests what the problem is. I can boot into Safemode without issue. So I have taken both 1GB modules out, to see if there was an issue, but the error still occured. I have also reinstalled SP3 while in Safemode, but that hasn't helped.

I have managed to get the PC to boot, after removing the PC from the domain, while in Safemode, and adding it to a workgroup, then rebooting. This allowed Windows to boot successfully, but the moment I added the PC to the domain again, and rebooted, the issue reappeared.

I read 1 post on a forum that suggested that the issue was caused by the FQDN being exactly 200 bytes long. This would appear to be why Windows boots successfully when removed from the domain. But I don't see how this would have changed between yesterday & today.

Can anyone suggest how I can get the Windows booting successfully, when back in the domain!

Thanks

Ben

Answer : Windows XP - BSOD STOP: C000021a The windows logon process terminated unexpectedly with a status of 0x00000005 (0x00000000 0x00000000)

I've tried to do a repair install of Windows XP, however, even that failed to solve the problem. The only way I have managed to get this sorted, is to completely reinstall Windows XP. The final machine ended up with the same machine name, IP address, service pack, software, and in the same OU, and having the same group policies applied to it as the previous build.
So as to what was causing this issue, I have no idea! Just glad it is now solved!