I am running Windows XP Pro, I went to uninstall a game, it said might not uninstall correctly if more then one user is logged onto the computer. I went to switch users, but then at the log in screen I manually shut down the computer (physically pushed the off button on the computer) after reboot, it began to load windows, then suddenly restarted. When the reboot was half done, I received the screen the prompts to select Normal Start up Mode, Safe Mode, or Command prompt. Normal mode and Safe mode do not work at all, when I ran from the command prompt, it said :

Stop: C0000218 {Registry File Failure}
The rsistry can not load the hive{file}
System root\system\32\config\software
Or its log or alternate
It is corrupt, absent, or not writeable.

This is as far as I can get. Any help would be appreciated, thanks. If any more information is required, please let me know.