Intellitype 6.1 Will not install

I've had major problems with Wireless Entertainment 7000 keyboard -- after
about 6 hours on the phone with very nice Microsoft tech reps I have a
minimally functional keyboard (mouse works fine). I'm running Windows Vista
Ultimate.

Lingering problem -- I cannot install Intellitype 6.1. At one point it was
installed but as part of troubleshooting I uninstalled it, intending to
immediately reinstall -- big mistake! -- when i try I get an error to the
effect the software version is already installed you must unsinstall before
proceeding. . . I've spent an additional few hours on the phone trying
everything under the sun, removing registry keys, etc., etc., etc. finally
the Microsoft rep said they'd done all they could and if I wished to return
the Key board call. . . . Surely SOMEBODY in Microsoft know what the darned
setup program is looking for that stops the install. . . surely. Any help
would be much appreciated. Thanks