Annoying "Messenger Service"

You know this Messenger Srevice that keeps sending some annoying popups in some Windows XPs? Well, I know that you can stop them from being sent if you go to your Command Prompt and type in "net stop messenger". But, its only momentarily. When I restart my PC I will have to stop this annoying Messenger Srevice again. Does anybody know how to stop it for good?

its a system service. just disable it from the MMC

start, run, compmgmt.msc

services, messenger (double click), and then select disable.

thx ill post again if i have another problem with this.