I have a strange problem on my PC. I run XP with automatic updates. I also have Norton Internet Security & Antivirus, which automatically download updates every day.
Yesterday, following a routine reboot, the PC would not restart - instead of the normal login screen, it very briefly displayed a dialog box which mentioned lsass.exe, and then immediately rebooted, going into a cycle of startup and reboot.
Suspecting it could somehow have been infected with the Sasser worm (which attacks the lsass.exe file), or something similar, despite having Norton Antivirus installed, I decided to boot using a DriveImage CD, and recover a backup image of the boot disk, which I keep in a seperate partition on another physical drive. I turned off the PC for 30 seconds (in case the worm can survive a reboot)
Surprisingly, the CD wouldn't boot either - it got through the initial process where it draws a progress bar along the bottom of the screen, then displayed "Please wait" for about 10 seconds, and then abruptly shutdown, turning off the power.
So I decided to try the Windows XP Installation CD - same thing - it gets part way through and then shuts down abruptly.
Next I tried the "Ultimate Boot CD" (ultimatebootcd.com), and finally was able to boot the machine into the CD's menu.
I decided to use one of the utilities to delete, recreate, and format the primary partition. Then I tried the DriveImage CD again, and this time it booted successfully.
So, I restored a week-old disk image and rebooted - and the system promptly shutdown again!
I guess it's possible that my backup image was infected, in which case reinstalling Windows onto a clean partition might work, but I'm puzzled as to how booting from recovery CDs would not work until the partition was cleared.
I also considered that it could be a hard disk problem, but I've run the Maxtor check disk utility (from the ultimatebootcd), and it appears to be fine.
Any ideas?