It is quite irritating that MSN Messenger pops up every time you start windows.
To disable Messenger MSN from running at startup, try the following :
(1) Go to the start menu >> RUN >> type "regedit" >> Press enter.
(2) The Registry editor will now have opened. Navigate to the following Key:
(3) Now create a new key by selecting Edit from the main menu bar. Now select New then Key. Name this new Key: Messenger .
(4) Now select the newly created Messenger Key and create another new Key. Only this time we are going to name it: Client
(5) Next we have to create a DWORD value. So Right Click the new Client Key and select New then DWORD.
Name the DWORD PreventRun
Set's it Data Value to 1.
Now restart Windows XP and you will have successfully Disabled Messenger MSN.