Media for What FireWall to run?

What FireWall to run?

I'm sure that this has been beaten to death on this group but.....

I've run the free version of ZoneAlarm for more years than I can remember. The last build however has played hell with both PC's here. I run Mozilla suite, XP-Home and I have not loaded SP-2 on either PC's. I constantly have to shut down ZoneAlarm in order to access the Web. I've recently un-installed it and am currently running the last free version of Kerio

2.1.5 which I really do not have much knowledge of.

Any suggestions other than ZoneAlarm for a free firewall that will handle both outgoing and incoming traffic? I did try the latest build of Kerio and it slowed my internet down by approx. 60%.

Thanks for any guidance given.