I have a brand new Windows Vista Business PC. I can setup a vpn to connect to one site - where the site is hosted on a Windows 2000 Server - and this works fine. When I setup a vpn to connect to another site - hosted by a Windows 2003 Server - I never get past the validating userid stage. Eventually I get an error 806 [GRE problem] and the event log on the 2003 server records the same error. I can connect to both sites no problem from a Windows XP PC on the same network, through the same router in the same office (a few feet away). I have had someone from another company connect a vpn to the 2003 server and their connection worked fine (though they were running Vista Ultimate and had a different network setup).I am at a loss how to diagnose this - if I can connect from one PC in the office doesn't that mean there isn't a problem with routers blocking protocols? The router logs shows GRE packets being exchanged when I connect from the XP machine.Any help appreciated.

Hi, Please temporarily uninstall the antivirus program and disable the firewall on the Windows Vista machine to check the result. I suggest uninstalling the antivirus program, because some filter drivers may be still active even if we disable/stop the antivirus function. Hope it helps.