Received wisdom here in the UK is not to rely on Windows Firewall 'cos hackers learn how to circumvent this in infant school. I've been well-served by Zone Alarm's free version for some years now, but I have a problem configuring this to allow my other home workgroup PC to access the internet. This it appears can only be done by reducing internet security to Medium. I tried upgrading to ZA Pro and couldn't find out how to configure this either, other than with only Medium protection. So at present I can either rely solely on Windows Firewall, which configures itself fine but query how effective, or run ZA on Medium. Which is likely to be safer?