Feedback to the DX4WIN Vista compatibility question says that v7.02 has compatibility problems, but v7.03 doesn't. You can download v7.03 by right clicking on the link to the 7.02 download, copying the shortcut, and pasting it into your browser address bar, then change 702 to 703. I just tried it and it works. Upgrade fees may apply, depending upon which version your licensed covers.
Nelson, KU0A