My radio does not have 240 to 260 MHz. However, I have successfully programmed the radio using this software. It is very difficult to find the proper driver for the USB to radio cable. I used my basic computer which runs Windows 10.
Many other programming software works better with my old Windows XP machine.
The readout on the KT-8900 makes it difficult to make sure that all options were programmed properly. I have not used it to transmit yet for that reason. Instructions on the radio are still sketchy to me. But Windows 10 and the software does seem to work.