Well, I’ve finally solved a problem that I’ve been struggling with for days. On Friday my VPN connection to the University of Southampton was working fine, and then on Saturday it wouldn’t work. At that point, I assumed it was a problem at the university and waited until this morning to contact their IT support department. After a number of telephone calls we established that it was a problem with my computer, as other computers in my house could connect to the VPN fine. At this point they marked the issue as resolved and told me that I’d have to investigate it myself – which, although frustrating, I could understand.
While trying to solve this I did a lot of Google searches, and found a huge number of forum posts from people who were having VPN problems in Vista. Eventually, however, I found the result that helped me – and I’ve described the solution below.
Suddenly VPN connections in Vista stop working. When you try to connect to a VPN it sits for ages at the “Connecting to VPN” dialog, and then gives you Error 800 – VPN unreachable. However, even thought it says the VPN is unreachable, the VPN server can be pinged fine.
I eventually found a good solution on a forum (http://www.vistax64.com/vista-networking-sharing/112970-pptp-stopped-working.html). It involves running some commands on the command-line to uninstall and then reinstall the VPN drivers. So, firstly, open the command window (by clicking Start, typing cmd, and then pressing Enter) and type in the following lines, pressing enter after each one:
netcfg -u ms_l2tp netcfg -u ms_pptp netcfg -l %windir%\inf\netrast.inf -c p -i ms_pptp netcfg -l %windir%\inf\netrast.inf -c p -i ms_l2tp
(that’s a lower-case letter L in the bottom two lines)
After running those commands, VPNs should be working again – hopefully! Let me know in the comments whether this works for you or not.