An alternative if you use DSL or cable is to use an inexpensive NAT capable router (with rebates the router can end up costing less than buying firewall software - got mine at Circuit City for a net $10).
It lets you use multiple PCs on the same internet connection and also completely stealths your machines from the outside world. Even if you don't disable the Messenger service, you can't get popups. If all you've got is dialup, there are a couple of modem/router combos that used to be available that would work similarly.
It lets you use multiple PCs on the same internet connection and also completely stealths your machines from the outside world. Even if you don't disable the Messenger service, you can't get popups. If all you've got is dialup, there are a couple of modem/router combos that used to be available that would work similarly.