What version of Windows are you using? Have you tried different USB ports on the same PC (your post doesn't mention it)? I feel compelled to mention that your cord may be spotty and giving out.
If you're running Windows 8/8.1 I suggest installing Windows Phone from the Store, or if you're on Windows 7 I suggest installing the Zune software. I don't believe Windows Phones are supported or recognized on Windows Vista or earlier, but I can't say for sure as I've never tried.
EDIT-Most USB cords that start to give out will usually last longer without TOO many problems as a simple charger plugged into an outlet. Because USB ports have a vastly lower voltage than standard wall chargers/USB-wall brick combos, coupled with the fact they are better for data transfers than charging your phone (again, low voltage=slow charging), your cord sounds like the real culprit.
If nothing else try plugging in another micro USB device with the same cord and see if it works. If not then your answer is indeed the cord.
12-21-2014 03:20 PM