Are you asking about ARC96? Was the software already on your tower? If it previously was on your tower and you tried to install it again, uninstall the old program first. Is the software on another computer not in use? If so, uninstall it from that computer. I believe you are limited to installations on 2 computers only. Some of the sites on the Colorado DTRS system use 700 MHz frequencies which the PRO-96 and PRO-2096 are unable to trunk track.