Security for Longhorn 5048

I had a problem with finding a security suite for Longhorn 5048. Zonealarm Security Suite, andAvast did not work at all. Norton went haywire and bombed. The ones I have found to work are McAfee 9 and AVG, Clamwin, and eTrust do work. The McAfee Personal Firewall does work as well. For best practice tho always utilize a hardware firewall as well.