How to disasble windows file protection

I'm not sure if I can really follow instructions online or they are just bad direction.

But I'm trying to disable Windows File Protection and nothing seems to be working. I even tried to throw the windows xp cd key back into the disc drive so that it would re-install the "corrupt/updated" files but it wont even do that.

http://www.microsoft.com/whdc/winlogo/drvsign/wfp.mspx