Remote Desktop into a LAN with multiple PC's

[YeOldeStonecat]

If you want to RD into 3x different PCs on a LAN behind the same router..you have a couple of choices..

Get a router that supports a direct VPN connection to it..so you can connect to the router..and be given access to the entire LAN.

Or...do what you're attempting...open/forward ports on the routers firewall. However..you can only forward a port to a single LAN IP address...so port 3389 can only go to 1x PC. If you want another PC to be made available through the NAT..you'll have to change the default port..something like 3390 or 3391.
http://support.microsoft.com/kb/306759

And..from the remote PC...you add a colon ( : ) to the IP address..followed by the custom port.
Example say you WAN IP address is 64.63.62.61...from your house..you'd type this into the RDC>..
64.63.62.61:3391

[bilbus]

or you could set your router to foward ports this way

Outside port 3389 to inside port 3389 192.168.1.100
Outside port 3300 to inside port 3389 192.168.1.101
Outside port 3001 to inside port 3389 192.168.1.102

Most home routers support port redirection from a outside port, to a diff inside port.