How to install an unsigned driver on Windows 8
Windows 8 by default will not let you install unsigned drivers. In order to install an unsigned driver, you can follow the steps shown below to start Windows 8 in "Disable Driver Signature Enforcement" mode.
Move the cursor over the top or bottom right corner or the screen and it will show extra options on the right side of the screen (This is the new Charm Bar in Windows 8). Choose the Settings option (icon looks like a Gear).
on the left hand side and then click Restart now
button on the right
Click Avanced options
Click Startup Settings
Click the Restart
Choose the Disable Driver Signature Enforcement
and hit the Enter key to start Windows
You should now be able to install the driver needed. After the driver installs, you can reboot the computer and it should revert back to enabling driver signature enforcement again.