lsass.exe - Application Error

Dell Dimension 5150, XP Home, SP2.

Suddenly, upon boot-up after the Windows welcome screen, the following message appears...

lsass.exe - Application Error
The instruction at "0x00401082" referenced memory at "0x00000000". The memory could not be "written".
Click on OK to terminate the program
Click on Cancel to debug the program

Clicking either OK or Cancel makes the Error message go away, but then it's just a black screen with the cursor. It stays like that and doesn't continue booting. You need to hold down the power button to turn it off.

I have tried Safe Mode, but get the same message. Also tried Last Known Good. I booted up from the Windows CD and from the recovery console did a chkdsk /r which didn't fix anything.

I also tried to run a Repair Install from the Windows CD, but it won't work.

Any ideas??? Thanks!

 

have you tried the fixboot command from the recovery console

 

Yes, I tried fixboot and fixmbr.

I guess the first thing I need to determine is if this is the result of a virus like the old sasser worm, or a legitimate SAM problem.

Any ideas?