It depends. SFC pulls files from the i386 (cache) directory. If these are infected too, then SFC won't fix it. If SFC asks for the windows CD, then the files will be replaced with the original uninfected version.
Yeah, I thought it made sense.. it's just that I'd never heard of it and hopped the OP would clear it up..
And I was considering suggesting a SP3 CD in case the OP didn't own a Windows XP CD...
Thanks for pitching in.