If you would rather do your own editing, then, locate SYSOC.INF in the \Windows\INF folder (hidden file and folder). Open it in Notepad and locate the line: msmsgs=msgrocm.dll,OcEntry,msmsgs.inf,hide,7
Remove the word 'hide' from the line and save the file. After making the necessary changes, you'll be able to see MSN Messenger in the Add/Remove Windows components list. You can then remove it for good.
Another alternative, without editing the registry is Click on Start-> Run then Copy the following command and paste it
RunDll32 advpack.dll,LaunchINFSection %windir%\INF\msmsgs.inf,BLC.Remove
(Source:
Asta Host Web Productions http://www.astahost.com )
Good luck!