When you install Windows XP Service Pack 1 (SP1), Windows adds a new feature called "Set Program Access and Defaults" to the Add or Remove Programs tool in Control Panel. You can use this feature to remove Windows Messenger from the Start menu, the desktop and other locations.
For additional information, consult Microsoft Knowledge Base Article 332003,"How to Change Your Default Programs and to Enable or Remove Access to Microsoft Windows and Non-Microsoft Programs."
One thing you need to remember is that if you use the Registry Editor incorrectly you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Please use Registry Editor at your own risk.
To prevent Windows Messenger from running, use one of the following methods:
Windows Messenger 4.0 or later on a Windows XP Professional-based computer
Click Start | Run, type gpedit.msc and then press ENTER.
Double-click the following items to expand them:
Local Computer Policy
Double-click Do not allow Windows Messenger to run and then click Enabled.
Click OK, and then quit the Group Policy snap-in.
NOTE: Group Policy Editor (Gpedit.msc) is not available on Windows XP Home Edition-based computers. In addition, this method also prevents programs that use the Messenger Application Programming Interfaces (APIs) from using Windows Messenger. Microsoft Outlook 2002, Microsoft Outlook Express 6 and the Remote Assistance feature in Windows XP are examples of programs that use these APIs and that depend on Windows Messenger.
Windows Messenger 4.0 on a Windows XP Home edition-based computer
Start Windows Messenger.
Click Options on the Tools menu.
Click the Preferences tab, click to clear the Run this program when Windows starts check box and then click OK.
NOTE: This procedure does not prevent users from manually running Windows Messenger, but it does prevent Windows Messenger from running automatically each time that you start Windows. If you use Outlook Express or Outlook XP, Windows Messenger may start automatically each time you run Outlook Express or Outlook.
To prevent Windows Messenger from signing in when you run Outlook Express:
In Outlook Express, click Options on the Tools menu.
On the General tab, click to clear the Automatically log on to Windows Messenger check box.
To prevent Windows Messenger from signing in when you run Outlook:
In Outlook, click Options on the Tools menu.
On the Other tab, click to clear the Enable Instant Messaging in Microsoft Outlook check box.
Windows Messenger 4.5 or later on Windows XP Home edition-based or Windows XP Professional-based computers
Start Registry Editor (Regedit.exe).
Locate and click the following registry key: HKEY_LOCAL_MACHINE \Software \Policies \Microsoft
On the Edit menu, point to New, click Key and then type Messenger for the name of the new registry key.
Click the new registry key: HKEY_LOCAL_MACHINE \Software \Policies \Microsoft \Messenger
On the On the Edit menu, point to New, click Key and then type Client for the name of the new registry key.
Click the new registry key: HKEY_LOCAL_MACHINE \Software \Policies \Microsoft \Messenger \Client
On the Edit menu, point to New, click DWORD Value and then type PreventRun for the name of the new DWORD value.
Right-click the PreventRun value that you created, click Modify, type 1 in the Value data box and then click OK.
Quit Registry Editor.
This method also prevents programs that use the Messenger Application Programming Interfaces (APIs) from using Windows Messenger. Outlook 2002, Outlook Express 6 and the Remote Assistance feature in Windows XP are examples of programs that use these APIs and that depend on Windows Messenger.
John Gormly is a regional technology director for a leading public accounting firm, a position he has held for the last 15 years. He is responsible for all aspects of technology, including PC support, LAN/WAN infrastructure, telecommunications, project management, training, IT deployments and personnel management.
This was first published in February 2005