Domain Controller can't receive inbound pings / Firewall can't be enabled

Question

I can ping everything from the domain server but it doesn't show up on any ping sweeps from client machines.

Also, the firewall service is off but can't be turned on. It says that there is another service using it. Is that normal?

Here's a screen shot;

http://yfrog.com/mqfirewallfj

Answer 1

I hate to be chicken little here, but any time firewall or antivirus services are compromised, it's a good time to check for malware & do a virus scan from boot.

If those are ruled out, are there any other roles or applications running on the server? That may help point to what's interfering.