Question : Problem: Trouble with Windows XP/2000 remote connection to Windows Server 2003

I'm having trouble establishing VPN connections from any Windows clients to my Windows 2003 Server.  We have a static IP that goes to a D-Link Router.  This router is set up to forward all incoming information for that IP to the internal IP of the server.  Remote Access/VPN is installed on the server.  Everything was working just fine until a couple of weeks ago when all connections started being refused.  I really don't even know where to start with this problem.  I'm kinda new to VPNs and Remote Access.  Any help would be appreciated.

Answer : Problem: Trouble with Windows XP/2000 remote connection to Windows Server 2003

DFL-300. That adds a new option. You have set up the VPN endpoint to be the windows server. With that router you can also make it the VPN endpoint. If you should want to do that, it is a totally different configuration, let me know. There are advantages to both. However, with your current configuration, you want the PPTP server disabled. Enabling will actually block access to the Windows server.

Instructions for configuring port forwarding can be found at the following link, however it is for the http service, just substitute the PPTP(1723) service. Also somewhere on the router there should be an option "PPTP pass-through". This allows the GRE encapsulation protocol. If that were the problem you would have a 721 error, and you may yet.
Are there any other routers or modems that are combined modem and router units? If so they will have to be dealt with as well. If so, please provide make and model.