I think i picked up a virus after my anti-virus expired, anyways when i downloaded a virus removable tool from microsoft it crashed . now all it will do is start up like normal, with the Dell logo's and all, but when it comes time for windows to load, it goes into a blue screen and says stop. c000021A { fatal system error }  The windows logon process system process terminated unexpectedly with of   oxc0000005. ( OXOOOOOOOO  OXOOOOOOOO )  the system has been shut down. does anyone know if this can be repaired or how i can get it running again.. thanks