I agree with the gentlemen above on the ZoneAlarm recommendation because for a free program it serves its purpose and the PRO version is that much better, but honestly if your that worried about safety and security go with a hardware based firewall. Heck i use both software and hardware on my end. Most often its just a peace of mind thing because the more defence the better right? well as long as your happy go with software but for a business it never hurts to go both.