I have a Win7 SP1 computer A (up to date) that is trying to access computer B (also Win7 SP1) behind a TS Gateway (SBS 2008).
When Computer A connects to Computer B as the user, they get: "The credentials that were used to connect to xxx did not work."
When A connects to B as Admin they get: "The number of connections to this computer is limited"
When A connects to a random C, on the same network, behind the same TS Gateway, it works fine.
When my test bench or another computer on A's network connects to B, it works fine.
(B can remote to A with no difficulty).
a) There's nothing wrong with the certificate, because A can connect to other PCs in B's network. b) Ditto the firewalls. c) There's nothing wrong with the RDP file, it works fine from my test bench. d) I can't find even the attempt to connect in B's event log (or the TS server event log) for the user. For the admin I can see the connection logged as successful (the WIn7 machine itself is throwing up the "To many connections" after the security procedure. e) Clocks are in sync (for encryption)