[solved]Unwanted (Update Available)

When I fire-up my PC,I always get this pop-up window from "Y!Messenger"...."Update Available....Upgrade now-Y! Messenager has new features for entertainment,personalization and productivity".Then there's a Yes/No box at the bottom of the window.I get so tired having to click "No" every time I turn on the PC.I think I remember maybe ONE time it gave me the option to never show this message again so I check marked that box.Does any one know how I can some how block this window from appearing every time the PC is turned on? Thanks guys

 

This should stop it.

 

I've been struggling to reformat my HD and have been absent a few days.The following worked for me and thanks alot Deke,...Went to C:\Program Files\Yahoo!\Messenger\------(Changed the name of this...yupdater.exe...to this...noyupdater) and restarted PC and the 'Update Available' popup window DID NOT appear. Thank all you guys for (I like to tinker with my PC),......Robert