Windows 7: Explorer.exe - Application Error

The error states:

explorer.exe - application error

The application was unable to start correctly (0xc0000022). Click OK to close the application.

When I click OK, i just have a black screen. I can get the task manager going by hitting control, alt, delete. I've tried to start explorer.exe from the file menu, but get the same error.

Help?

Welcome aboard, Wahid

if it occur when you are on desktop, try : SFC /SCANNOW Command - System File Checker

But if it occure before you get the desktop, you try : SFC /SCANNOW : Run in Command Prompt at Boot

let us know the result.