I have just recently encountered this problem on my home computer. Windows XP constantly reboots or shuts down during bootup (during the splash screen, twice its reached the login screen then rebooted).
I have restarted in Last Good Configuration as well as Safe Mode, but bootup only completes to Safe Mode. I don’t think this is a hardware problem as there has been no hardware changes in the past 5 months. I have used the Recovery Console to restore kernel32.dll (as Microsoft suggests) but to no avail.
The problem started a day after I had uninstalled Norton Scan, as ESET Smart Security is already installed on the machine. There is no BSOD (I have turned off automatic restart on error) and the boot log shows that everything is normal. Is there any way I can find out what the problem is (via built-in or safe mode friendly diagnostic tools), or will I have to reinstall XP?
The machine specs are
Windows XP SP2 (updates current til last week)
512MB RAM
Intel Pentium 4 (Northwood @ 2.8Ghz)
GeForce FX 5200 (81.98 Forceware)
Eset Smart Security 3.x
Thanks for any help.