OK, I know nothing at all about Vista, so I'm not best placed to advise here, but I've just unistalled and reinstalled my drivers in XP just to check how it works.
If anybody knows better here, do correct me.
The Driver installation needs 3 files:
ftdibus.inf (in \Drivers)
ftdibus.sys (in \Drivers\i386
ftd2xx.dll (in \Drivers)
When RB is installed from CD, these are copied across into the Drivers directory as shown in the picture below. Note that if you are using a different version of RB, then the name of the directory will reflect the version you have installed.
So, to install the correct drivers, if you have the wrong ones installed, fire up the Device Manager and right click on AirNav RadarBox, or Unknown USB Device and select Properties.
Select Driver > Update Driver and select "No not at this time" then Next
Select "Install from a list or specific location" and click Next
Browse to the \Drivers directory as per the diagram below.
Click Next
Accept the warning about unsigned drivers and click Next
The install will probably stop looking for the ftdibus.sys file, so browse to the \Data\i386 directory and click Next
If the install should then continue. If the install stops again, take a note of the file that the driver update is looking for.
This is for XP, so don't know if this works the same for Vista.