Changing the default Windows Shell in Windows 7
The default Windows shell in Windows 7 is the Windows Explorer, however you can replace it with other shells such as, the command prompt, Windows PowerShell or custom built shells. This may become handy when computers are running specific tasks and you want to restrict their usage or free up resources taken by the default shell. However, remember that if for example you set the command prompt as the default shell, users can still load the default shell and other hidden applications.
Plan ahead before changing the default Windows shell as it may not be easy to revert back and render your computer unusable. For instance, to run the registry editor from the command prompt, type regedit or to log off, type logoff. Furthermore, Microsoft doesn’t support custom built configurations.
To start the registry editor, type regedit in the Start menu search text box and press enter.
In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon edit the string Shell by replacing Explorer.exe to cmd.exe for instance. You need to log off and back on to see the change.
Key: HKEY_LOCAL_MACHINE \SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
Value: [Explorer.exe or Cmd.exe or PowerShell.exe or others]
A word of caution – incorrectly editing the registry may severely damage your system. The above modifications are intended for Windows knowledgeable users who are familiar with the registry editor. Users are also reminded to take a backup of the registry before making any critical changes.