kb : MSvpn01
Date : 1-24-2009
Manufacturer : Microsoft
Version : Windows XP SP2 (may affect other versions)
Problem :
Microsoft Windows VPN Error 800: Unable to establish connection. This can occur for a variety of reasons and the solutions vary. Microsoft provides its own solution but it did not work for me.
Solution :
http://support.microsoft.com/kb/311272/ DevCon
devcon.exe install c:\windows\inf\netrasa.inf MS_PptpMiniport