BleepingComputer.com: registry file failure error

I am trying to assist my son with his laptop. He has a Dell, running windows xp professional. He is getting a registry file failure error and the suggestions found for that error do not work for us. I tried using the last known working configuration but it did not help. Unfortunately, the disk for that version of windows has disapppeared so I can't do anything requiring using the disk. Can I install Windows xp home on his computer or is there another option I haven't considered?
Please let me know if I have not included enough information. I don't know all of the particulars on his laptop, but if you tell me how to get them, I will do my best.
Thanks in advance!!
caly

Quote

What is the exact error and when does it happen?

error says:
stop: coooo218 (registry file failure)
registry can't load the hive (file):
\systemroot\system32\config\
software or its log or alternate
It is corrupt absent or not writable.
Beginning of physical memory dump.
Memory dump complete (I think I recalled this line correctly, missed writing it down)
contact system administrator or tech support

More than likely a repair install is needed here. If you know someone that has a windows XP disk and they will let you borrow it you can use that one. Your windows product key is located on a sticker that is more than likely on the bottom of the laptop.

Corrupted Registry, Config.sys Missing or Corrupt - http://support.microsoft.com/kb/307545

Louis