Bonnie001, Britec, dannyjks,
I know this is an old post and someone may like to redirect it but I have just had the same problem :
STOP: c000021a {Fatal System Error}
The Windows Logon Process system process terminated unexpectedly with a status of 0xc06d007e (0×00000000 0×00000000).
The system has been shut down.
Background : Client got hit with a phone call from our friends in Pakistan offering to fix the PC when the client declined the offer problems started, they did all sorts uninstalling AVG installing other virus checking software until it just blue screened with the above message.
I downloaded and updated DR web and it found things and rebooted no joy the blue screen came back. Tried to run MS dart it could not work as it could not find the OS the problem was I needed to go to bios and switched raid to compatibility - by the way the hard drive was a sata and the PC a DELL Dimension 9150 just for your interest.
After making those changes the MSDart cd found Windows XP ( By the way the os I was working on was Windows media centre 2005 ) and I tried to do a system restore it found loads of restore points but when I clicked it did nothing. I did files repair it found corrupted explorer.exe claimed to have fixed it but on reboot same blue screen.
Moving on and research on the net I cloned the hard drive so I had a backup then started work on the clone, fitted the broken hard drive into a working XP PC and then renamed the following files :
csrss.exe > changed to csrss.exeold
winlogon.exe > winnlogon.exeold
win32k.sys > win32k.sysold
Then from good PC replaced the above with good clean copies. Shutdown.
Placed the clone hard drive with the changed files mentioned above back in to original PC and everything works fine. I hope this will help others in the same situation the fact this worked for me will not mean it will work for you as it could be hardware including ram the had drive itself BUT it is a great place to start good luck it came a little late for Bonnie001 but I just wanted to share what I have found and done to fix my problem.
Also with portable cd installed Malwarebytes and updated ran it and it found 200 or so infections all sorts of rogue security programs etc, next all the usual virus checking & one last thing make a new restore point turn off and then on the system restore after your virus and malware checking has come up clean you don't want to reinfect yourself by restoring stuff in the restore folder, everything is good now
take care
tmy
