Getting rid of Windows File Protection

I have read several things about how to get rid of windows file protection. I have been able to hex edit a copy of the needed dll, sfc_os.dll, found in c:\windows\system32, but have been able to copy it to the original folder to have the changes take effect. I am using XP Pro with Service Pack 1. I read you could reboot and start in the dos prompt, but with xp, even in the start up dos style propt, its still emulated; when i try to copy the file, it still says its in use.

I was wondering if there was some form of DOS i can boot from a disk, so i can avoid loading the xp files.

thanx for any and all help.

non amava