I got it unstuck by:
- installing the two updates listed here (by Elder Geek); and then
- following the procedure listed on InfoWorld.
Tedious? Yes. Yes, it was. At least I had plenty of time to write my last post while the updates were downloading and installing!
Edit: When stuck at “Preparing to install,” I checked the system tray per RogerSC’s post here and it worked.
As of 2016/11/28: The short version is below. See the linked pages for more details and any updates.
- Manually download the updates noted below.
- Set Windows Update to “Never check for updates.”
- Stop the Windows Update service, and set it to Manual startup. (Use services.msc.)
- Manually install, in this order, rebooting as prompted:
- Install the latest rollup. As of writing, that is KB3172605.
- Change the Windows Update service back to Automatic (Delayed start) and start the service. Reboot.
Tested on Win7 Pro x64.