It's probably ok, also look at zonealarm, that's a good one, and seems to run well. The one I'm using on Vista is PC tools firewall plus.
http://www.pctools.com/firewall/
Seems very good, I have had no issues with it, highly recommend it. Also, download AVG Antivirus free edition.
free.grisoft.com
Also very good program, free to download, free updates, doesn't get much better than that.