(Largely agreeing with Pluto.)
Leon, IIRC from previous discussions your 4G acts as a wireless hotspot. I have one of those Telstra 4G hotspots.
Is this adapter some Telstra specific thing or is is an over-the-counter WLAN (wireless LAN) adapter - probably USB. If it is a WLAN adapter, either:
- Windows should be able to find the right drivers,
- the manufacturer will have Win8 versions, or
- the manufacturer reckons there is no money in writing and certifying Win8 drivers and you'll have to buy a new one that is Win8 certified.