Missing or Corrupt\windows\system32\config\system??

Hi all,
I was wondering if anyone can assist me with my problem. My Gateway laptop all of a sudden wont boot. It gives me this message ( Missing or Corrupt file ) \windows\system32\config\system. The laptop is running XP pro with SP1.

I have an XP cd to repair it, I just need guidlines on what to do.
So far Ive gotten to the part where it says ( Install XP on this Partition or Repair XP ) need help on what to do after that.I have no admin passowrd on it so Ill be able to get into it. I just need further assistance on how to run repair or recovery.

Any other way I can acces my files in that HD?? I need to recover my homework and other documents.

Thanks.

 

http://support.microsoft.com/?kbid=307545