A handful of the radios RT Systems addresses have built in USB capabilities. These radios would not require the use of a specific RT Systems cable. A standard USB A to B or USB A to Mini B cable is what would be used in place. On occasion, the drivers for the built in USB don't always install as expected or Windows doesn't put them in place properly for some reason.
If this happens, the drivers can be downloaded from the link below,
These drivers apply to the following radios:
The drivers downloaded from the link above are in a ZIP folder and would need to be extracted after downloading. You'll want to click on file downloaded and it will bring up the contents of the zipped folder in another window. At the top of the page, there should be button for "Extract" at the top of that screen as pictured below,
In earlier version of Windows, the extraction process may differ. But the end result would be the same. If you have trouble installing the drivers, contact Tech Support for further assistance.