Seems that you need to go through Device Manager to install the drivers. The .vxd file is a driver file. If you go into Device Manager, locate your uninstalled device (should have yellow markings beside it), then go through the procedure for updating/installing the driver...all should be well.
Just guessing...but I suspect that double-clicking on that .exe file should start the install of the drivers, without going throug Device Manager.
I have no idea what that .cas file is, but I would guess that it's nonessential.