Alright. sadly i didn't create the problem or see it happen. My CASE fan has a issue where it gets loud and he hit it and it works. So friday my brother wanted to use my computer and the case fan was loud so he claims he shut the computer off. He tried again soon after and still the same thing. So he hits the case fan a few times and shuts if off and gives up. About a half hour later he claims he started the computer and he gets the following screen which is still poping up. It loads windows XP i get the bars after that blue screen and it says this>

STOP: C0000218 {registy file failure}
The registry cannot load the hive (file) :
\systemroot\system32\config/SOFTWARE
or its log alternate.
It is corrupt, absent, or not writable.

Beginning dump of physical memory
Dumping physical memory to disk: 1.....100

its a Pentium 4 3GHz system that i build. i though it was the RAM (1.5GB i have) and i pulled it out cleaned and back in and still gives me error. At this very moment im running "memory test" from a live CD from linux.... seems to be passing it. Could windows be currupted? how did he do it? he claims he never touched the power bar he shut it off normally. My Technician from work told me to TAKE the hard drive out and make it external drive connect it to windows system and it should fix the error? should i try that? I have a back-up image of the install anyways i just dont wanna use it if i dont have to. thanks in advance. The stop error message is a corrupted registry file, please see this Link.well i formated the drive and tried the back-up like i always do using macruim reflect and now it wont work? it always worked and now nothing. after the back-up is done it just sits at a blank screen after the bios with a flashing cursor??Either the Reflect image is bad or your BROTHERS repeated whapping of the PC has DAMAGED the HDD...

Try a new HDD.