You experience one of the following symptoms when you try to establish a virtual private network (VPN) connection by using “Layer Two Tunneling Protocol with IPsec” (L2TP/IPsec) from a Windows client computer to a VPN server.

• Symptom 1

  The Windows client computer is running Microsoft Windows XP, Microsoft Windows Server 2003, or Microsoft Windows 2000, and you try to connect to a VPN server that is running Microsoft Windows Server Code Name “Longhorn” or Windows Vista. However, you cannot connect to the VPN server. Instead, you receive an error message the resembles the following:

  741 The local computer does not support encryption.

• Symptom 2

  The Windows client computer is running Windows Server Code Name “Longhorn” or Windows Vista, and you try to connect to a VPN server that is running Windows XP, Windows Server 2003, or Windows 2000. However, you cannot connect to the VPN server. Instead, you receive an error message the resembles the following:

  742 The remote server does not support encryption.

After you upgrade a Microsoft Windows XP-based computer to Windows Vista, or you upgrade a pre-release version of Windows Vista to the release version of Windows Vista, third-party network-related programs may no longer function.

You experience this issue with programs such as virtual private network (VPN) programs or load balancing and failover (LBFO) programs.

A special MS Knowledgebase article listing VPN clients and their current status as far as Vista compatibility. Keep reading →