Failure analysis and solution for error code 721 when win7 system fails to connect to VPN

            
Fault Cause Analysis:
1, 721 error is caused by your computer in the internal network, because there are multiple computers in the LAN, the server can not correctly determine which computer is the specific, so the connection will prompt Error 721.
2, Win2003 routing and remote access to build vpn, some places dialing prompt error 721, the VPN policy is changed from pptp to L2TP.
3, the router prohibits PPTP connection.
Solution:
1, click “ start & mdash; & mdash; run & rdquo;, type “ regedit & rdquo; command and click & ldquo; OK & rdquo;;
2, in the registry editor, find The following registrations are HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Class/{4D36E972-E325-11CE-BFC1-08002bE10318};
where is the network adapter for the WAN Miniport (PPTP) driver.
Note: "000x" represents several options below 0001-0009, the general PPTP is 0003, the specific one by one click to view.
3, click on the menu bar & ldquo; edit & mdash; & mdash; create & mdash; & mdash; DWORD value & rdquo;;
4, enter the ValidateAddress command press Enter. The default setting for this value is “1” (open), so you need to set it to <;0& rdquo; turn it off;
5, restart the computer.
Win7 system connection VPN prompt 721 error solution is shared here, and later encountered error 721 problem can be solved by the registry editor.
The above is the fault analysis and solution for the error code 721 when the win7 system fails to connect to the VPN.