Bootcamp Macbook Air thinks my USB 3.0 ports are USB 2.0
On Windows, you need drivers in order to have everything working fine. In this case, the bootcamp should install it for you right after Windows installation. It installs all drivers: trackpad, graphic card, webcam, USB 3.0; as well as some bootcamp utilities that allow you to use the F10, F11, F12 as volume keys for instance.

If you didn't get this part during your installation, you just need to use the USB-stick you installed windows with and run the bootcamp software on it (it's the only .exe you'll find). 

OR

See this Apple Support page to download it again (64-bit, Mid-2013 MacBook Air): http://support.apple.com/kb/DL1721