Fix Critical Problem Error while Unlocking or Switching Users in Windows 7
You might be facing trouble while unlocking or switching users in your Windows 7 or Windows Server 2008 R2 PC. In that case Windows shoots up the following error:
Windows has encountered a critical problem and will restart automatically in one minute. Please save your work now.
Then, the computer restarts.
When this problem occurs, the following event is logged in the Application log:
Log Name: Application
Source: Microsoft-Windows-Wininit
Date: <Date>
Event ID: 1015
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: <Computer>
Description: A critical system process, C:\Windows\system32\lsass.exe, failed with status code 255. The machine must now be restarted.
According to Microsoft KBA976586, the problem also occurs while using “Switch User” option in the Windows login screen. Microsoft has released an hotfix to fix this problem. You need to request it from Microsoft, then download and install the same.