Diagnose XP error, where to start?

[eaglescouter]

I know of two XP pro machines that suddenly will not load all the way into XP.

Both of them get thru the post, show an XP loading window the blue bar moves for a short while then the PC reboots.

Upon reboot the system reports that it was unable to boot properly and offers options to boot normally, safe mode, last known good configuration, etc. All options return the same failure after the XP loading window and another spontanious reboot.

Both machines are stock (not overclocked) and have been running reliably for a full year. Neither user does anything more than office use (word, excel and minor web surfing).

Where should I start in the process of diagnosing and repairing this problem?

Thank you for the suggestions.

[turd]

Well I would start with the recovery console:
http://technet2.microsoft.com/WindowsServer/en/library/1ed79310-13ee-4352-8e1b-bbb59bc15b961033.mspx?mfr=true

and run the fixboot and fixmbr commands:
http://technet2.microsoft.com/WindowsServer/en/library/1ed79310-13ee-4352-8e1b-bbb59bc15b961033.mspx?mfr=true

then you could move to a repair install:

http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/tips/doug92.mspx


This is assuming that your XP is corrupted by perhaps: virus?

Could be hardware, like clogged HSF, but unlikely on both at same time..

[XxNightfirexX]

If you haven't already tried, try booting into safe mode. If you can get it booted up that way, then go to "run" and type msconfig. In the config utility that comes up, go to the startup tab and uncheck everything listed there.

Reboot in normal mode. If it boots up successfully, then go back into msconfig, and one by one reactivate each startup item that you previously unchecked, and reboot after each item. If you come to a point that it won't boot, then you've got a starting point as to what's causing the problem.

Now if you can't boot into safe mode, then I'ld try what turd listed, as that would suggest system corruption to me. It could also be hardware as turd said. You may want to run memtest on them, or try out a different hd and see if it boots ok. I'ld lean towards a software problem though, since it's more than one machine, either something you installed that's in the startup of each machine, or a virus that got into your network. If you can get it booted into safe mode, and connect to the net, you may want to run an online virus scan too.

[eaglescouter]

Nope, neither machine will boot into safe mode either.

Thanks for the input, now I've got a place to start :)

[eaglescouter]

I gave the fixboot a shot, upon reboot the problems remained.

I attempted the reinstall of XP using the repair option and the hard drive format was listed as Unknown.

Now using knoppix to pull off the files that had not been backed up, will follow with a full NTFS format during the XP reinstall process.