Supplement 29.05.2014 - a star deduction: Here go some of the keys with a Win7 HTPC not. So neither volume up, volume, mute nor the Play / Pause function can be used. Even with extra tools like EventGhost no event is signaled when printing on these buttons. I suspect this is due to the missing drivers. Unfortunately none is supplied and do a search on the internet also was unsuccessful.
If tracked down jmd. A driver for the device, he was to report your views.