First check wht happens in safe mode.

Then boot to recovery console and run chkdsk /p and chkdsk /r.

"Heidi" wrote:

> When I turn my computer on, I get a winlogon.exe error message. Then when I
> turn off the computer, it automatically restarts, and I have to shut down
> twice to get it to turn off.
>
> I disabled "automatically restart" so that I could see what error message I
> receive. I now get "Fatal System Error Stop c000021a".
>
> I'm not sure what to do now. Any help would be appreciated.