If you can connect to the PPTP tunnel server, but you cannot perform a domain logon to the target network, verify that you have configured the connection to your PPTP server to enable you to perform a domain logon to the target network.
To Verify Your PPTP Configuration
1.In the Dial-Up Networking folder, right-click the icon for your PPTP server connection.
2.Click Properties.
3.Click the Server Types tab.
4.In the Advanced options box, make sure the Log on to the network check box is selected.