Thanks for that tickmike. I'll bear it in mind for the future. I have a hardware firewall via my router (Netgear DG834GT) which has always done a very good job. I hadn't realised that it was possible to use an old PC as a hardware firewall - just never thought about it I suppose! I want the software firewall to monitor outgoings from my PC both for my sake and for the sake of other net users. Kerio seems fine so far but advice and suggestions are always welcome!
Your are welcome Jazz.
Smoothwall is Linux based and very solid,it will run on a 486 upwards, It can be used for one machine or to protect a school or a firms network with 100's of machines, It has a built in 'Proxy Server' which is useful to see a log of what url's are being used by your network and you can block any website if you want.
You have to turn off the router firewall, but you can still have software firewalls as well on each machine.
Smoothwall has a world wide help forum.
You can download the free software, then burn an image to a CD rom, then load that into your old computer and it self loads, configure a few settings and you have a firewall that nobody has got into yet.
Michael.