Balloon Messages

I am running Win XP Pro and noticed that when I loaded the system, balloon messages kept “popping” up at the task bar. An article in PC Magazine suggested to turn them off by modifying the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced variabel by entering a DWORD, give it a name and value of zero and then re-start the machine. I did this and most of the balloon messages were eliminated, all except the one that asks you to update Windows. I am continually plagued with this message. How does one turn it off??