I currently have a Cisco ASA 5505(ASA Version 8.2(1), and ASDM gui version 6.2) and a Windows 2008 R2 server with one NIC card. Currently the router is connected to the interent sucessfully using the 'outside' interface(devices connected to the 'inside' interface have access to the internet and are assigned IP addresses via DHCP on the Windows 2008 Server which is also connected to the 'inside' interface) When connected with a client on the inside interface I can establish a VPN connection with the W2008 server, however when I try to connect through the internet I cannot. I have tried researching this on the internet, but have not had much luck. I know it has something to do with pptp port and allowing gre, but I am not familiar enough with configuring Cisco devices or the language they use, to configure this router. I feel as though I am missing something small but very critical. Any help or feedback you can provide regarding this issue is most appreicated, thank you.
*Edit: I have attached a network diagram of what I am trying to accomplish, and I have also attached a dump of the current running-config.