Sometimes after logging on, an annoying advertising popup is waiting for me from Windows Messenger. How can I disable it?

Windows messenger and MSN Messenger are two different things. If you are speaking of the advertisements that come as message windows (where you click ok to close them), then you can do the following but be aware that by doing this you disable some networking capabilities. 1) You can run a firewall and block ports 137, 138, 139 and 445 (but this hurts networking capabilities). 2) Else, go to Start, All Programs, Administrative Tools, Services. Scroll down until you see Messenger in the list (alphabetically). Double click on it. In the dropdown menu on the general tab, select disabled. Then stop the service. The next time you reboot, and every time thereafter, it will be disabled (and no more of those annoying messages). You do not have to reboot now as it is disabled. This also prevents some networking capabilities. If you are not a part of a LAN, don't worry about it.

Oops, almost forgot... Another way of accessing Services is to right click on My Computer then select Manage. Click on Services and Applications then click on Services.; same window.

Thanks, fanatic. Problem solved.

No problem... Those irritated the hell out of me too. Bad for gaming. Cya