not sure if you mean messenger service or windows messenger the chat program.
windows messenger removal:
click start/run and type:RunDll32 advpack.dll,LaunchINFSection%windir%\INF\msmsgs.inf,BLC.Remove. click ok.
messenger service removal:click here to do this manually click:
start/control panel/performance and maintenance/administrative tools/services.scroll down to "messenger" double click it and choose "disabled" as the start up option and restart the computer.