windows/system32/config/system corrupted

My nephew encountered this problem with his netbook. I fixed this using the Windows Xp CD and used the Recovery Console. I replaced the corrupted file by typing:

c:\windows\repair\system c:\windows\system32\config\system

After a few days, the error suddenly appeared again. I did the procedure above and was able to fix the problem. But it keeps on coming back.

What could be the possible cause of this problem?

Note: I also examined the netbook itself. Based on my observations, whenever I switch-on the unit, I hear a strange sound(scratches) inside it. I suspect a Hard Disk problem here but I’m not sure.

Thank you in advance.

Regards,

Jeff