PC will not reboot after security scan was run.

PC is a Gateway GM5268 with Windows Media Center Edition. It is used strictly as a PC and there is an identical unit for back-up.

A security scan had been run and the PC was set for “reboot”. The following message appeared each time attempts were made to reboot:

” Windows could not start because the following file is missing or corrupt: \WINDOWS\SYSTEM32\CONFIG\SYSTEM ”

Knowing that there is more than one way to approach this problem, my questions are: 1. “What proceedure would be the best to restore operation with no files lost?” 2. “Isn’t software available to assist in this process?” 3. “If so, which would you suggest?” … It is essential to try to save certain picture files, if at all possible