Alternatively, if messenger does not appear in the Add/Remove Programs applet in the Control Panel. In order for it to show up there, you must first edit the file named sysoc.inf. This file can be found in a folder named INF, which is a subfolder of the Windows folder (or in some cases the winnt folder, depending on how your OS was installed). You can open that file in notepad. Look for the following line:
msmsgs=msgrocm.dll,OcEntry,
msmsgs.inf,hide,7
and remove the word "hide" while leaving the commas on place. Close and save the file, and then open the Add/Remove Programs applet in the Control Panel, so that you can remove it like any other program.