Problem with Droid Razr, help please?

So I've plugged my Razr into the computer via USB, and the installing new hardware window came up for half a second, then reported that it failed to install new hardware. Since then I've been trying things like downloading the MotoCast USB drivers and trying anything I can to get the Razr recognized by the computer, but nothing seems to work...it is charging, though.

In the My Computer folder the computer doesn't even recognize that an additional device has been connected...

I just want to root my phone :[...any help is much appreciated!