I have a Dell desktop with Windows 7, and I am unable to log in. When I try to log in, it doesn't recognize my face or my husband's. We didn't set up FastAccess and don't know how it became activated. If I try to log in with my password, the computer shuts down. I can't get past the log in screen, so trying to uninstall isn't an option. I have gotten past the log in screen once and completed a diagnostic that indicated that the system was fine. Any suggestions?