After not using Sonar for a few years I decided to install it on a new machine.  I downloaded all of the set-up files and update files, but when I go to do the install it says, "Cannot locate the required version of the program on this system. Please install the correct version of the program to use this patch."  I ran the (ESD_Setup) file.
 
I'm running Windows 7 64 Pro on a substantially configured machine. I thought maybe I had to install my Sonar 7 first, but that did not help.

8.5 was the first upgrade available as a download. To reduce the size of the download, the 8.5 downloadable upgrade requires SONAR 8.0 be installed first. SONAR 8.0 was only available on disk. So you will need to find the 8.0 install disks. Since then, all upgrades starting with X1 are complete versions of SONAR.