Windows 7 IP-Forwarding doesn`t work!

[felfely]

Hello everybody.

I have a problem about IP-Forwarding.
I set the registry value of "IpEnableRouter" but IP-Forwarding does not work.
I tested it by vmware in this scenario:
I have a win7 Guest OS, win7 Host OS & a modem. I enabled registry value of "IpEnableRouter" in Host OS & set the default gateway of Guest OS to IP address of Host OS.
When I ping 4.2.2.4 in Guest OS, Requests don`t forwarding fron Host OS to the modem.

Can you help me?
Thanks a lot.
Ya Ali.