Windows firewalls

Okay I know this is a bit off topic, and probably get me flammed... i have a friend who runs a Windows server (no, there is no way to convert to linux as she's using a hosted box. App is also locked to Win32, so...) and it's routinely hit by portscanners and has been hacked at least twice now. Anyone know of *GOOD* and *DECENT* Firewalls? Anything but Zonealarm.. it sucks balls. She's also not really in the mood to pay for the software, so i'mlooking for opensource options. i was thinking of an IPtables solution, but i don't think the host will allow cgywin installed on the box. Thanks in advance Joe Brouhard jbrouhard@chansata.com