A lot of people want to know how to remove the MSN Messenger service from XP... here's how:
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. You will now have an entry in add/remove programs. Do what you will :)
OR (XP Pro Only) leave it installed, but tell Windows to never let it run. If you're running XP Professional, you can use GPEDIT.MSC to prevent Messenger from loading. Otherwise, even disabling it in startup won't cause it to "always" not run. NOTE: Outlook, Outlook Express and some Microsoft web pages can still make it load.
Start, Run and enter GPEDIT.MSC Computer Configuration > Administrative Templates > Windows Components > Windows Messenger You can now modify whether it starts initially and/or whether it's to run at all. UPDATE: I have recieved some email that say this fix slows down outlook when starting, that is because outlook wants to start messenger when it starts, the easiest and fastest way to disable messenger and still have a quickj starttime with outlook is to rename the exe file, located here c:\program files\messenger\msmsgs.exe, to something other than msmsgs.exe, such as msmsgsnew.exe.