I applied the December Windows Update patches. My computer went into a reboot loop at the end of the installation so I reverted back to the previous restore point. Upon investigation, all patches had applied except KP4530734 (December Security Monthly Quality Rollup for Win 7). I reapplied all the other patches except that one, and the computer rebooted fine. I then tried re-installing that one and again it went into a reboot loop, restarting about every 6 minutes. I waited more than 2 hours just to be safe, but again had to abort the patch and revert back to the last restore point taken before attempting to apply that patch.
On a positive note, apparently that patch includes the new full-screen MS-nag message about Win7 End-Of-Life that will be displayed in January so at least I won't be seeing that.
Any recommendations on how to proceed?