Can you please give more information to where are you signing out? (Email or Windows itself)
- First do a hard reboot, remove the battery and unplug its AC adapter then press and hold the power button for 20 seconds then try it again.
- If it doesn't work do run System Restore and restore it back to an earlier date or time before the problem even happened.
- Here's how to perform System Restore:
- http://windows.microsoft.com/en-PH/windows-8/restore-refresh-reset-pc
- If these doesn't work your last option would be to reinstall Windows.