VPN issue with PPTP and Windows Vista

I have been using VPN connection on Windows Vista since very early CTP version of Vista. All worked fine till today. Without of any plausible reason, the VPN has stopped working. I spent probably four hours of my life to fix this. Honestly I spend four hours for ever for some stupid Vista-Networking thing and hope this post will help you to spend few hours longer for some much more interesting peace of life.

When you start VPM connection you will notice that the connecting window is hanging for minutes and after all it pop-ups you some error message. Please do not read it, it will confuse you more than you can expect. Because of this I will not paste it here. :)

More interesting message is in event log:

CoId={3AB760CF-41C9-4267-999F-57AC7E079137}: The user *** dialed a connection named *** which has failed. The error code returned on failure is 800.

This message is not confusing, but the entropy of useful information could sometimes be high. Unfortunately in my specific problem, this message has not useful information at all (too).

If you have installed Virtual PC 2007 on your machine, it can happen that some windows update (I would really like to know which one) destroy some kind of mapping between VPN connection and WAN Miniport driver. Usually, the VPN should be bound on WAN Miniport (PPTP) like shown in the picture below:

After this mapping is damaged, you will notice that instead of PPTP L2TP is mapped.

To workaround the problem open the dialog with properties of physical network adapter (for example WLAN adapter) and notice "Virtual Machine Network Services".

Select it and press button "Uninstall". After few seconds try to connect via VPN again. This should work now, without of restarting of the machine.

hhhmmm, one may think now, this sounds too simple to be true. :) This is true, because after uninstalling of "Virtual Machine Network Services" the virtual machine will no more work. Fortunately, this can be easily fixed too. Start VPC and one dialog will appear, which notifies you that virtual network service are missing on the machine. Press button "Yes" and VPC will install it again automatically.

Last, but not least. If you are happy user of T-Mobile UMTS express card, the card will in this case not work too. The error message, which describes the problem would have less entropy than zero if would be mathematically possible. If you really want to read some much more crazy thing please go here.

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