Windows 8 forces drivers to be digitally signed and checks that signature with it's known driver signatures at home. This is a problem if you are trying to install and use something like fastboot/adb which Redmond may not have drivers for.
I was personally trying to install this as I did before on Windows 7: http://forum.xda-developers.com/show....php?t=1379875 and in order to install this we need to "Disable driver signature enforcement"
Steps to be taken:
1.) Bring up Charms by mousing over to the right of the screen
2.) Go to Settings
3.) Change PC Settings
5.) Scroll down to Advanced Startup > Restart Now
6.) Trouble shoot
7.) Advanced options
8.) Windows startup options
10.) Choose F7 (I believe) or click on "Disable driver signature enforcement"
Install the relevant driver (In my case Universal driver) under Device Management
This allowed me to install the Universal driver for both my Nexus devices. Anyway, hope it helps ya'll.
(Mods if posted before feel free to delete/merge/whatever.)