Hi i have recently had a lot of laptops (different makes) with a problem i cant solve unless i back up data and re-install windows 8.1. It always happens the same. After installing updates it restarts to the login screen. You put your password in then the screen stays black.Also happens with no password. I can ctrl alt delete and start task manager but when i try to system restore it hangs on initialising or eventually says system restore didn't work. The laptops were all from last year clean installs with oem 8.1 from Murphey iso. All previous updates installed fine. The March updates seemed to have caused this problem. Has anybody had the same problem and if so have you been able to fix it. Thanks in advance