It should work, the Fritz program came with the board.
There is just a tick box with DGT on it. When I click it, it opens the rabbit config screen, where I can select COM4, board goes live straight away, every single time, but I can't get any move to register in Fritz. Been trying everything I can think of since Friday. I can see the PC gets my moves on the board tab on the rabbit config screen. It's just Fritz 14 doesn't receive them.
I wonder whether the problem is that my PC is 64 bit and the Fritz program and rabbit thing are 32 bit. Cojntacted support a few days ago, but no reply yet. If not solved tomorrow it's going back.
It /does/ work with Frotz, I have used it that way. I think you have to enable it in Fritz also, thre is a DGT section in the settings or on the options bar