VMWare Player client can't access internet any more (DNS problem?)

Question

I'm using VMWare Player 2.5.4 for a longer time on my Windows XP machine. In the last week the guest OS stopped being able to connect to the internet anymore: pinging up to the gateway/dns-server (my router) works, but pinging an domain, e.g. kde.org, times out (but works on the host). I have not installed anything or changed something on the guest OS. On the host OS (my XP machine) I've installed Microsoft Security Essentials in the last week — could that cause the problem? How can I work around it?

Answer 1

It turned out to be the Sunbelt Personal Firewall whose license expired these days. Did not know that I have to pay an annual fee for using it in registered mode (which is necessary to activate the gateway-mode needed for VMWare).