I am trying to use an xp pro box as a router. I have two network cards on two different subnet, 192.168.4.x 192.168.69.x. I have enabled ip forwarding by editing XP registry but it didn't work. Any idea? Thank you

Does each computer have the default gateway define on each computer in there subnet? every computer in the 192.168.69.(1) must have a default gateway of 192.168.69.(1) if your using one as your gateway, and the smae is true for the 192.168.4.(1) if your using one as your gateway, all the computer on that subnet must have there default gateways define as 192.168.4.1, then if your have ip forwarding turn on , eveything should work,, unless you have a firewall blocking something. I would load a sniffer on one computer on each subnet, you should see packets coming and going from the other subnet, that is one way of seeing what is going on.

" have enabled ip forwarding by editing XP registry but it didn't work. Any idea?" Wrong procedure. Google Internet Connection Sharing and follow the procedure or use the network wizard.