What should I do if I get error 720 after upgrading win8.1?

From win8 update to 8.1, I found that vpn login appeared 720. I saw various unclear methods on the Internet. Here I introduce a simpler method that Xiaobai can understand

1, first right click on this computer to open the device manager, then we found that the network adapter, wan mini port (ip /ipv6 /network monitor) appeared a yellow exclamation point, it seems that the problem is here.

2, right-click update is not used to click to uninstall and can not uninstall online There are many ways to delete after modifying the registry, but for Xiaobai, the registry is a nightmare, so we press the following

3, right wan mini port (ip) - update driver software - browse computer to find driver

4, select from the computer device driver list - cancel Show compatible hardware - then pull down to find Universal Mobile Broadband Adapter - then install it next time

5, after installation is complete, it will prompt error number 10, ignore it and return to Device Manager Uninstalling the newly updated Mobile Broadband Adapter

6, then restarting the computer is very important. It may be a bit slow to restart the computer, because the computer is reinstalling the adapter that was just deleted, and after opening the device, open the device manager and find it. The exclamation point disappeared, now try again with vpn

Note: There may be a short network disconnect when updating the driver. If it fails, please use all the adapters with yellow exclamation point. The same method is fixed.