Model: vhtv, highway tv,Xtreme
Operating System: Windows 2000 (Note: might work with other versions of this os.)
Just install the software for windows 98 as usual then download the software userport from the internet, here is one link http://www.embeddedtronics.com/public/Electronics/minidaq/userport/UserPort.zip.
After that run this program and start the driver "userport.sys".
Run the your vhtv program and voila..
Ps:I tried with windows 2000/XP and the driver works in those SO.