How to install Android Fastboot/ADB drivers under Windows 8

It's easy to work around. The drivers signature enforcement simply has to be temporarily disabled.

In the following way, you can do that.

1. From the Metro Start Screen, open Settings (move your mouse to the bottom-right-corner of the screen and wait for the pop-out bar to appear, then click the Gear icon).
2. Click ‘More PC Settings’.
3. Click ‘General’.
4. Scroll down, and click ‘Restart now’ under ‘Advanced startup’.
5. Wait for the computer to restart.
6. When the boot menu opens up, Click ‘Troubleshoot’.
7. Click ‘Advanced Options’
8. Click ‘Windows Startup Settings’
9. Click Restart.
10. Wait for the computer to restart again and when it prompts you to select options, make sure you select 'Disable driver signature enforcement'.
11. After Windows finishes booting you should now be able to install the Fastboot/ADB drivers.

Voila, you should now be able to install the Google Fastboot/ADB drivers and continue messing around with your Android phone :)