PORT Greyed out/CODE 28 - W8.1 Pro x64

Okay so I've searched and searched.

On a Surface Pro 3 - trying to get my Nano working.

I've installed 1.6.3, I've tried the nightly. I've installed the drivers from the nightly. I've done the 'unsigned drivers' thing. I've rebooted after installing drivers. Nothing seems to work. I keep getting the PORT selection greyed out.

Now, if the whole Port thing isn't necessary for getting arduino running in eclipse, that's cool and I just need to know that. I already have eclipse setup for my STM32F0 board.

What's actually really, REALLY frustrating is that I was able to actually get some code on my Nano the first time I booted up 1.6.3. It all worked peachy. Then I shut it down and restarted the program and I'm now SOL.

If anyone has any ideas, it is greatly appreciated.

Thank you in advance.