I use the remote IP address and the account of the other pc. I am sure that
Remote Desktop is allowed on both computers and the port is opened on both
computers.
That's correct. You'll need the Internet IP address of the remote computer,
not the internal IP address (unless the remote computer is plugged directly
into the internet and not behind a firewall). If it's behind a firewall
(Linksys, Netgear, etc) you'll need to allow the RD port through that device
and on to the computer.
Also remember that XP has the built in firewall and most anti-virus programs
have built in firewalls as well.
I have a Linskys router, having trouble figuring out how to open port 3389.
When trying to initiate Remote Desktop Connection, keep receiving message"
the client could not connect to the remote computer. Remote connections might
not be enabled or computer might be too busy"