what is this file and why is it missing?

<windows root>\system32\ntoskrn1.exe. I ask because for some reason it prevents my other computer from starting up. I end up having to re-install windows, and I've done it so many times that I had to call microsoft for another product key. I've run virus scans/spyware scans, ccleaner etc. (nothing comes up) but it just still keeps happening. It'll work fine for a few days and then *poof* "file is missing or corrupt". I once took it to a computer repair guy and he didn't know why it happens (he ended up re-installing too, which I could've done and saved $100). But I'm not going to deal with it anymore and would just like to know what the heck could be causing that to happen and just what that file is for and how would I go about fixing such a thing incase it happens to the computer I'm on now. So thanks in advance.

I don't know much about computers (can you tell?) but it's a compaq presario s6300nx windows xp pro v 2002 (and i've updated each time i had to re-install), if there's any other info you need.. I have no idea. I want to throw it off my balcony. :cry

 

Most recommend Method 3 as a fix here: http://support.microsoft.com/kb/314477/en-us

If you did a few complete reinstalls and the file is ntoskrnl.exe; could be a bad stick of memory has been reported to cause this error. Have you tested your memory?

Confirm that file name was a typo or not? if typo fix it again and

Then check your memory
http://www.majorgeeks.com/MemTest_d350.html

If no errors in memory Check Disk
http://support.microsoft.com/kb/315265