unplug, uninstll drivers,
--! 1) install all windows hotfixes given in the link above FIRST.
-restart
-2) plug back in the head phones. wait to reconized.
3) restart PC
4 re-download software here :
http://www.plantronics.com/us/product/gc780-surround-sound-windows
-install
-restart PC.
should work. ...
(only install the software, if your windows7 proprietary software has not already either "found it the correct drivers itself" or "it may also work without the drivers and give you 7.1 surround configuration in your windows volume mixer itself. and also if you want to use the USB headphones you will also prolly have to switch to them in the win vol configuration tab. )