Hello:
I got this problem for a long time I tried to reinstall my dell m4800 three time still does not change anything.
I am having Dell M4800 Precision Workstation, I recently install windows 8.1 on it. I installed the Dell data protection | security tool, it's running fine. I can login through fingerprint and password fine every time. However, whenever windows 8.1 install an update that requires restart to finish install, right after I restart, I input my password, swipe my fingerprint, but system keep saying login is incorrect, I just can not login. I use restart, the laptop won't restart, it shows restarting for 1 minute or 2 and goes back to login screen, not power off and on at all. I have to press power button to power down my laptop and power on again in order to logon, and after that, windows just running slow, I have to reboot several times in order to recover its speed. And I tried resinstall windows and everything 3 times the problem keep showing up, and I pay attention to windows update, I notice that as long as the windows update requires a reboot, the problem will showing up, there is not particular update causing this problem, anyone have any idea?
