How to fix Windows logging on and logging off immediately

This article provides a step-by-step guide on how to fix the issue of Windows logging on and logging off immediately.

SYMPTOMS

You may face this problem when logging on to Windows. When you type user name and password you are again presented with User name and Password dialogue box. You try hard to get in but to no avail.

CAUSE

You may not be able to log on to system using either Normal Mode or Safe Mode. This occur only when Winlogon service tries to load the Windows default shell (explorer.exe) and user shell (userinit.exe) from registry. This service searches for Explorer.exe and Userinit.exe in the following path of registry:

HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon

RESOLUTION

Edit these values and type the correct path of shell :

Shell = explorer.exe

Userinit=X:\windows\system32\userinit.exe

NOTE: These files may also be deleted by spywares. You may need to extract them using Windows CD. 

Steps for rectifying this problem:

• Log on to a networked computer.
• Run Regedit.exe
• Point your cursor to HKEY_LOCAL_MACHINE
• Select File > Connect Remote Registry
• Type computer name (infected computer)
• Navigate to the following location in registry of destination or infected computer

                        HKLM\Software\Microsoft\Windows NT\CurrentVersion\Winlogon

• Edit these two values in right pane:
  Shell
  Userinit

• Change these two values to

                  Shell=explorer.exe
                  Userinit = x:\windows\system32\userinit.exe

• Exit from Registry
• Restart Infected computer.
• You should be able to log on to computer.