got "Device Descriptor Request Failed" for one of my two arduino unos

I have two arduino unos on hand right now. One of them is working perfectly and can upload and run my sketches. Whenever I plug in my second Arduino Uno to the same port, I get a Windows error message saying the USB device malfunctioned and that Windows doesn't recognize it. If my first one works fine, there's obviously no issue with the cable nor the drivers. I'm concerned that my malfunctioning arduino isn't going to get better. I've followed multiple threads so far on this topic and none of them have fixed my problem yet. For reference:

http://forums.adafruit.com/viewtopic.php?f=25&t=52246

Thank you in advance to anyone who has time to help share their solutions.