Probably not. SFC only recovers corrupt system files. Take a visit to the MS update site and run a scan. SP2 should show up.
Downloaded and installed SP2 on my extra hardrive out of curiosity. After install of the SP2 and reboot I had windows explorer give the message that it had encountered a problem and needed to close. I then ran sfc from the original XP disk, which solved the problem of instability. My question is, did sfc negate the SP2 install?