Write these instructions down!!!
If you are still having problems, along with any Windows 8/8.1 users, it's because the drivers aren't signed. To install these drivers go to:
Settings->Change PC Settings->Update and Recovery->Recovery->Advanced Startup
The PC will restart, from there you will select:
Troubleshooter->Advanced Options->Startup Settings
The PC will restart again, it will prompt you with numbers to select. Select the one that says "Disable Driver Signature Enforcement" then when it boots, install Zadig.