How strange - I've just this minute been reinstalling mine after quite a period of non use due to the studio rebuild. I'm on Windows 7 64bit
I downloaded the latest drivers, had a little issue initially as I was trying to use a USB hub, but The Tranzport would not bind and didn't like that so I had to go direct to the computers USB port, installed in compatibility mode as administrator and all is now working perfectly.
Think Frontier are long gone, but you can still pick up Tranzport's off places like Ebay - I got a spare for about $30 a year or so ago and have it tucked safely away in my store room for a rainy day!!
I suppose you tried a reinstall as above??
Hope you get it working and I really hope its not a Windows 10 thing as I might have to upgrade from 7 to 10 one day - but at the moment, I'd rather have windows 7 + Tranzport than windows 10 without!
Nigel