Accessing Network Shares Over a VPN Connection in Windows Vista
It is not possible to access network shares from a Windows Vista machine over a VPN connection if Net BIOS over TCP (NetBT) is disabled on one of the machines or port 139 is blocked. A fix for this problem is available from Microsoft Support. Customers just need to call support and quote the following KB number associated with the fix
933468: SMB (port 445) does not bind on Vista over RAS connection
If you need help with the problem or the fix please contact rrasblog@microsoft.com
Aanand Ramachandran
Program Manager, RRAS
