Hello,There is something that I don't understand about Firewall with Advanced Security.I removed all the default rules (inbound and outbound) and set the firewall properties to block both inbound and outbound if an explicit rule does not exist. I set up a few rules (outbound) for my programs under Vista that need to access the internet and it works fine. However, I have a Windows XP installation in Virtual PC and I can access the internet completely unrestricted from that installation - even if I didn't set up any rules in the Vista's firewall to allow any programs running on the XP (virtual drive).Also, the outbound allow rules in Vista firewall I set up are per program, and not by destination, port, service, etc.Can someone explain why this happens. I see it as a security vulnerability but I might be wrong.Thank you.Stephan

Virtualisation happens at a much lower level, so Virtual PC will not be affected by Vista's firewall. The guest PC is effectively treated as a completely separate system and so the routing of network packets never actually reaches the Vista OS.If you want to protect the virtual PC you need to configure the firewall within XP as well.

Thank you.