Try to boot from windows vista dvd or if u have oem computer go to repair options !!ok
Boot to Win
RE
Click Command Prompt
option.
Type the following command:
C:
CD Windows\system32
ren cmd.exe cmd.old
ren magnify.exe cmd.exe
ren cmd.old magnify.exe
Restart computer
Click on Easy of Access centre left side bottom � Choose Magnify option � Command prompt
opens up
Type: net user