I have an XP home running SP3 and Nortons Security centre that would not load the desktop icons and or the start bar but would allow access to Task Manager. As a result of some digging decided that explorer.exe was coruupted. Ran from command line sfc /scannow. Carried out a reboot after and now the pc will not boot into any option (safe normal or last known good)Is my only option to insert the orriginal disk boot to the cd rom drive and run a repair install?