Cannot log in to Windows - The solutions
When you log in to Windows, the computer immediately saves your settings, logs off and returns to the login screen again.This is the result of a corrupt or invalid registry entry, which may have been changed by a virus or spyware. Therefore you are strongly advised to scan your computer for viruses and spyware as soon as possible.
Solution
Method 1
Try this method if you can start Windows in safe mode:
- Boot into safe mode.
- Click Start, Run and enter regedit
- Expand HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft \Windows NT\CurrentVersion\Winlogon
- Select the Winlogon folder.
- If the right-hand pane contains an entry named OldUserinit:
- delete the entry named Userinit
- rename OldUserinit to Userinit. - Check that the value of Userinit is "C:\WINDOWS\system32\userinit.exe," (the comma at the end of the string is important.) Note: if your Windows folder is not C:\Windows, modify the path accordingly.
Method 2
If you have a Microsoft Windows installation CD:
- Perform a repair installation.
Method 3
Try taking the hard drive and attaching it to another Windows XP computer as a slave, or by using a USB-to-IDE adapter. Alternatively you can try making a BartPE recovery CD and booting the computer from that. Any method can be used that gives you read/write access to the hard drive.
Often, the registry entry referred to above has been changed from userinit.exe to wsaupdater.exe. Therefore you have a good chance of success if you just copy Windows\System32\userinit.exe to Windows\System32\wsaupdater.exe
Method 4
Gain read/write access to your hard drive from another computer running the same version of Windows.
- Log in as administrator.
- Ensure that Windows Explorer folder options have enabled Show hidden files and folders.
- Click Start, Run and enter regedit
- Select HKEY_LOCAL_MACHINE
- Click File, Load Hive, then navigate to Windows\System32\Config on your hard drive (not the host system!)
- Select system and click Open.
- For Enter a Key name type anything.
- Expand HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft \Windows NT\CurrentVersion\Winlogon
- Select the Winlogon folder.
- If the right-hand pane contains an entry named OldUserinit:
- delete the entry named Userinit
- rename OldUserinit to Userinit. - Check that the value of Userinit is "C:\WINDOWS\system32\userinit.exe," (the comma at the end of the string is important.) Note: if your Windows folder is not C:\Windows, modify the path accordingly. This is the Windows path when the drive is in use in your computer, not the drive letter it has currently.
- When you have made the changes click File, Unload Hive.
Applies to
- Microsoft Windows 2000
- Microsoft Windows XP
Source : http://www.the-pc-guru.com