I guess you mean Netgear WRG614 v5
There's no point port forwarding without setting up a static IP first (I checked & your router does need one)... just won't work.
Some people have found that with the latest versions of LW, they need to port forward whereas with older versions they didn't have to. Don't ask me why!

Sounds like enabling UPnP hasn't done anything so maybe p/f's your other option if you want to use the new version.
Silly question, but have you double checked all your Win firewall settings?