To uninstall Windows Messenger completly from your computer
1. Using Notepad, open the file %windir%\inf\sysoc.inf 2. Change the line that reads
(delete the word "hide" but leave the commas)
3. Go to the Control Panel, choose Add/Remove Programs, and select the "Windows Components" tag. 4. "Windows Messenger" now appears at the bottom of the list. Remove it as you would any other application.
The other method to uninstall it completely, Go to Start > Run, then type in this and run it. (one Line)