Silly question - why are you still on Win 8.0? Get updated to Win 8.1 first. You need to go to the MS App store to do this.
There are numerous bug fixes in that update, plus more importantly you will still get Security Updates. Win 8.0 will not be supported into the future as MS expect you to update to 8.1
Once updated, I have a few notes I made somewhere to get Win7 to work that I can probably convert to Win8
Also try getting the modem to work with a cable first before swapping to working with Bluetooth.