When upgrading to Ghost Solution Suite 3.x from either Deployment Solution 6.9 SP6 or an earlier, the error message "We have detected that the Ghost Solution Suite Console is running on one or more remote computers" occurs and prevents installation.
The installation performs a check for other active DS 6.9/GSS 3 console. Closing these other consoles will allow you to proceed. If you have closed all known connections from remote consoles, rebooting the machine where you are upgrading will sever the connections from remote console, after which you can install successfully.