J-in-K,

Nope, it doesn't work to stop the service, that's the first thing I tried. It didn't even work to disable it; the service would reenable itself. Perhaps are advertisers are smart enough to run a little hack to enable the service... I don't know enough about the inner workings of Windows to tell if that's an open port.

Perhaps that's the missing link & you need to do BOTH -- the firewall prevents the abuser from reenabling the service?