You don't need to clear out the older version 7&9. You may just need to put in your Poser 11.X serial number and the serial you upgraded from if the 6&7 digits of your serial number say UD instead of RD. I just renamed my old Poser 11 in SM folder to 11.1 and the installer just picked up my serial info no problem. Because you uninstalled it may have deleted the references to the old information.
Also when I installed today at home Poser was written into the SmithMicro folder inside of Programs. When I tested at Work on a new machine which never had poser Before it was Loaded into Programs Poser, I think not sure the exact name, and that asked me for a serial number to continue.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13