Phone and computer won't connect?

I have an EnV touch from verizon wireless, and when I try to hook it up to my computer so I can add music, it won't connect. It has worked many times before, so I don't know why it isn't working now. When hooked up, my phone says it's connected to the computer and that it's charging, but when I go to sync it just endlessly says it's connecting. In windows media player, I'm in the sync tab. Yet nothing ever comes up. I've tried refreshing the devices many times.