Hello! Problem description I'm having some wierd problems with a L2TP VPN connection. I'm using Windows 7 Enterprise with Service Pack 1. I'm a software developer and use Visual Studio 2010 for my job. One of my customers has a VPN with L2TP setup. I need access to that VPN so I can retrieve his data. The VPN server that I need to access has FreeBSD. If I do a fresh install of Windows 7, including Visual Studio 2010, everything works great. I can connect successfully. I'm not sure about this, but since I updated my Visual Studio 2010 to Visual Studio 2010 Service Pack 1, I can't connect to VPN using L2TP anymore. At first I thought that may be a problem on the customers side but then I realized that I can connect to VPN with computers that do not have Visual Studio or computers that do not have the Visual Studio 2010 Service Pack 1 installed. I know that all of this make any sense but I'm out of ideas for solving this problem and I asking for your help/thoughts/suggestions. Thanks in advance. Some information: - The error when trying to estabilish a L2TP connection is 789: error during security negotiations with remote computer. - I can ping to that server, no problems. - My firewall is off. - The protocol is only CHAP V2 with optional encryption. - The server use certificate, not pre-shared key

1. First what comes to mind is revert changes - return to previous restore point. 2. There are some troubleshooting articles for VPN http://blogs.technet.com/b/rrasblog/archive/2009/08/12/troubleshooting-common-vpn-related-errors.aspx Regards Milos

Thanks Milos. Unfortunately there is no restore point but yes, I agree with you. Solution: I did a fresh install of windows and VS2010 without SP1 and "solved" my problem.