I've scoured the net and tried all the declared fixes, I've read every thread on XDA on this topic. Now I'm turning to the guys who know more about Windows than Microsoft. I realize this topic is not the normal fare around here but perhaps someone has a real solution. I have a Nexus 4, Windows 8.1 MCE. Both work perfectly, but no matter what I try I cannot get the ADB or MTP USB driver to load properly. Windows 8, 7, these methods work fine, not 8.1. There is speculation about the driver signing, but the workarounds I've tried do nothing. Anyone? Thanks!!