HTC one M8-- the sync manager version 3.1.46.0 usb connected pc does not recongnize anything. What should I do?

[AC Question]

HTC one M8-- the sync manager version 3.1.46.0 usb connected pc does not recongnize anything

Cannot put my music on my phone... Im seriously annoyed.. tried different usb, debugged, everything!!!!
Please help... I've lost over 4000 songs...