Greetings Rob,
There really is no way for it to "reinstall" itself, unless you haven't fully removed it.
You can fully remove it from doing this method -- close down Messenger if it's running (right
click the messenger icon in the notification area/system tray and click close). Then click
the start button, then click Run and type in (copy-paste if you like):
RunDll32 advpack.dll,LaunchINFSection %windir%\INF\msmsgs.inf,BLC.Remove
Then click OK.
Messenger will then be uninstalled. For more detailed instructions and screenshots, go to,
http://messenger.jonathankay.com/problem.aspx?ID=7
Also, keep in mind that Messenger has been on WindowsUpdates before, so you may also be
"reinstalling" it from there.
____________________________________________
Jonathan Kay
Microsoft MVP - Windows Messenger/MSN Messenger
Associate Expert
http://www.microsoft.com/windowsxp/expertzone/
Messenger Resources -
http://messenger.jonathankay.com