Try re-installing the driver.
Go to Device Manager (through Control Panel)
Click Network Adapters
Right Click the Ethernet, Network and WiFi Drivers, and select Uninstall.
DO NOT click the box that says "Delete all info..." leave it unchecked.
Wait a moment.
Click up the top and "Search for Plug and Play/New Hardware" and it will reinstall the Drivers.
Should hopefully fix the problem.
If you see any of the drivers with Yellow Triangles they need reinstalling, if this doesn't work, you then need to use another PC, go to the manufacturers website, and download the drivers from their. If this is the case with the network driver then do it on another PC and pop it on a flash driver.
Once you've got the driver, uninstall and check "Delete all info". Then run the setup.exe you downloaded in the driver folder and it will reinstall a new non-corrupted driver.