Yes, ZoneAlarm is usually pretty good. Check the system requirements, though. Don't use Norton IS fireware, though. It's buggy and doesn't interact well with Windows Explorer. If you use DSL or Cable, get a firewall, right away! If not (56k, dial-up, whatever), it's not as much of an issue. But, regardless, it's always a good idea to protect your computer from unwanted visitors by means of a firewall -- even if you don't have anything extremely important on it.