Disable virtual adapter:
Right click My Computer on desktop or Start menu.
Select Properties.
Click on Hardware tab.
Click on Device Manager button.
Expand network adapters branch of device tree.
Right click on WAN Virtual Adapter.
Select Disable.
Click Yes when asked for confirmation.
Test hardware adapter:
Right click on hardware adapter used by virtual network adapter.
Select Properties.
Click on the Diagnostics tab.
If errors are detected, a message is displayed.
Otherwise, select the data loopback test type (usually internal).
Run the loopback test by clicking Start Test
The test runs until clicking Stop Test.
Enable virtual adapter:
Right click My Computer on desktop.
Select Properties.
Click on Hardware tab.
Click on Device Manager button.
Expand network adapters branch of device tree.
Right click on WAN Virtual Adapter.
Select Enable.
Click Yes when asked for confirmation.