My client is running an SBS 2008 server with VPN server enabled. All tests and checks show that it is operating properly. When trying to VPN in from his home Windows 7 PC or his Windows 6 Pro notebook or from my personal workstation in my office, also running Windows 7 Pro, sometimes it connects quickly and efficiently as is my common experience with VPN, and sometimes it failes to connect with error 807 "Connecting to . . .". Port 1723 and Protocol 47 GRE is open on the server firewall the antivirus firewall, and the router firewall. The workstations are set to specifically connect via PPTP. Usually, when VPN connects, an RDP connection also works quickly. Likewise, when VPN fails to connect, RDP connects, but it may take up to 20-25 seconds for the login screen to appear, after which everything works smoothly. Turning off the Trend Micro Worry Free Business Security version 7 both on the server and the clients has made no difference. Windows XP Pro workstations fail with error 720. My client's office connects to the Internet via Comcast cable using their current Business Gateway device, which also serves as the network firewall. Comcast has checked the connection for me several times and we have exchanged the Gateway device for a new one. The same issues remained. The fact that at various times all these workstations can connect appears to indicate that my setup is correct. Does anyone have any idea why it will connect fine one time and then error out most others. Thanks in advance for your help.

Hi, ERROR_VPN_DISCONNECT 807: The network connection between your computer and the VPN server was interrupted. This can be caused by a problem in the VPN transmission and is commonly the result of internet latency or simply that your VPN server has reached capacity. Error 720: A connection to the remote computer could not be established. Due to this issue occurs on different Windows clients, I suspect the connection was interrupted by some software or router. Please test in a Clean Boot mode to see how it works. Meanwhile, if it is possible, please try another router or bypass it to check what the result is. Alex ZhaoPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.