i rarely shut my desktop windows xp computer off but it sounded loud last night so i did. i turned it on this morning and i got the message that windows could not start because the following file was corrupt or missing(windows/system32/config/system). the message suggested i reboot with the original setup cd and select 'r' at the first screen to repair the file. however, i can't find my original XP cd. what should i do? help!