Two Firewalls

Can someone please tell me how they find running another firewall on top of Windows XP?
Is any firewall more compatible than others?
Any conflict from XP firewall?
Thanks

The firewall XP comes with only blocks incoming connections. If a trojan or spyware attempted to contact the net it wouldn't stop it.

There are a number of firewalls taylored to suit various ********* skill levels. I would recommend you pick one to match yours and use it instead.