I am using Windows 7 Pro SP1. Other details about my system are in my signature. I can install and run PMS v 9.15.2, but I cannot install v 9.15.6. It gets stuck on initializing and gives a 0x800705b4 error (which appears to just be a timeout error).
I had an issue with my Windows update that had to be repaired before I could get new updates. I had to manually install a couple updates first, but my Windows update is working now and is up to date.
As I said all of my Windows updates are now installed. I have also tried repairing as well as uninstalling and re-installing PMS v 9.15.2. I also manually downloaded and installed Microsoft Visual C++ 2015 Resdistributable.
I have rebooted a lot and tried installing v 9.15.6 several times with and without PMS running, with and without my firewall running, and immediately following a repair of the existing v 9.15.2 PMS. So I think I have held my breath and tongue just right and each time I get the same issue and error.
Here is a copy of my install log - pastebin.com/LPT9Dq5v