Laptop boot problems

My girlfriend gave me her dead compaq laptop because she doesn't know anything about computers and how to fix them... thing is neither do I. I'm just smart enough to ask around and hopefully someone can answer.

Problem: Boot up windows (it's xp home) and it gets to the dos windows boot screen and sticks for a very long time. If i boot it up in safe mode, it will eventually take me to a blue screen saying something along the lines of

STOP: c000021a [FATAL SYSTEM ERROR]
The windows login process has terminated unexpectedly with a...(random numbers and letters)
The system has shut down.

and quickly boots back to the windows boot screen.

Do you think it's the hdd?should i try to reformat it, or boot from a cd?
thanks in advance to any helpful responses

I'd guess hard drive. Try a livecd, if it boots then it's your hd, if not something more serious. It's possible that it might be physically corrupted, but more likely it's just the filesystem is trashed and a format is needed.

>>1

most hard drive makers have a bootable test utility that you can use. for memory, memtest86 has a bootable cd/fd.

otherwise, yeah, just format it, reinstall windows and see what happens. it's probably just a corrupt installation.