What version of Comodo Firewall?
I'm not sure, but I would say 2.4, since svchost.exe is allowed Internet access by default in version 3 (?).
Go to
Security ->
Application Monitor.
Rule should be:
Action:
AllowProtocol:
TCP OR UDPDirection:
OutSource IP:
Any (or yours)
Destination IP:
AnySource Port:
AnyDestination Port:
53, 67, 68 (add 80 if you use Windows Update)
Anyways, if it's CFP 3...
Go to
Firewall ->
Advanced ->
Network Security Policy. Find svchost.exe and change it from blocked to allowed.
Cheers,
Ragwing