Resolved Cannot boot to desktop after Windows Update

I used Windows Update and did 15 updates. After that it asked me to restart. I restart and it boots to the desktop. I wait for a pretty long time but everything is unresponsive, I am not able to click anything but the mouse moves around fine. Usually I just turn off the computer and turn it back on and it'll be fine. But after I turned off the computer this time it cannot boot up to the desktop.

I have tried to start the computer in all 3 of the Safe Modes, Last Known Good Configuration, and Start Windows Normally. None works. This is the message I get:

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

You can attempt to repair tihs file by starting Windows Setup using the original Setup CD-ROM.
Select 'r' at the first screen to start repair.

How should I fix this problem?

 

How to recover from a corrupted registry that prevents Windows XP from starting

 

Thanks, the instructions weren't very clear but I got by. You can mark this thread as [Resolved].