copy sam C:\windows\system32\config\sam
Now, it should be noted that the above procedure does not ALWAYS work...I seem to bat about .500 with this working...
in the past it was all or nothing, but just the other day, it kind of worked...I was able to start windows, but a lot of things didn't work.
Anyway...try that. If it does not work, you have a second computer....can you pull a harddrive?