I have cable access and after having the week from hell dealing with constant pop up ads through windows messenger, (6-8 an hour after locking the system down with zone alarm pro)I've found a quick and easy solution to the problem. This affects mostly people who use Windows 2000 and XP. Go to
http://grc.com/default.htm
and download a program called Shoot The Messenger. It's FREE and quickly shuts down your windows messenger and your problem is solved. After 3 days of constant bombardment from people wanting me to buy their software to stop them from spamming me, it is nice to go back to working on the 'puter in peace and quiet.
If you use Norton's Firewall, there is one more thing you have to do. Go into Norton's Firewall and disable "monitor instant messaging" - this actually calls the msmsgs.exe service about every 2 minutes - so it's best to disable that option.
I hope this helps some of you guys that are getting tired of this wonderful new way people are finding to spam us.
Have a good one