Does sfc.exe work with both Windows XP and Win 7? If so, do you use it the same way on both OS versions?
I've used it a number of times over the years on XP, & on 98SE before that ! It worked just fine. http://www.thewindowsclub.com/how-to-run-system-file-checker-analyze-its-logs-in-windows-7-vista
You use it the same way on both operating systems, but on XP, sometimes it will ask you to insert your XP CD. There are instruction here for XP users detailing how to have sfc load any neeed files from your hard drive, so you don't get prompted for the Windows CD. On Vista and later operating systems, you are never asked for your Windows DVD.
My - remote - experiences with sfc.exe were negative: it works restoring the system to the initial configuration and it sometimes make conflict with third part softwares that you installed. Don't ask me which softwares: unlucky I don't remember.
I never experienced any problems as a result of running sfc. But, on the otherhand it usually hasn't fixed problems either. It does not restore your system to the original configuaration. What is does is scan for and replace missing or corrupted system files.
If you suspect system corruption due to malware, for higher assurance that malware doesn't interfere with sfc, it can be run offline.