When I first got my Nexus 7 last fall I had no problems connection to my Windows 7 pc with MTP. Now my Windows 7 pc and my new Windows 8 pc don't even acknowledge that I've plugged the N7 in. When I plug in my LG phone it sees it right away, but is using the old USB Drive method. This tells me the problem is probably on my N7. I've tried the developer debug stuff several times. Anyone have any ideas on what else I can try?