SharePoint 2013: Product Configuration Wizard stuck

Problem

You have installed SP1 or some other cumulative update on all your farm servers without issue.  You then run the SharePoint Products Configuration Wizard on each machine.  It completes without issue on one or two machines, but then, on the next machine, it nearly completes but then appears to remain stuck on configuration task 9 of 10.  You wait an hour, but it still remains stuck on task 9 of 10.  You then check the Upgrade Status page in Central Administration

Solution

1. Delete the SharePoint Products Configuration Wizard dialog.  Terminate the process of necessary to remove it.
2. Open the Services.msc panel, and then look for the SharePoint Timer Service.
3. Stop this service.
4. Open Windows Explorer, and then navigate to the cache folder at:C:ProgramDataMicrosoftSharePointConfig.
5. Look for the most recent cache folder, and then open it.
6. Delete all files in this folder EXCEPT cache.ini.
7. Open the cache.ini file in a text editor, and then randomly modify the number, but keep it at the same number of digits.
8. Save the cache.ini file.
9. Start the SharePoint Timer Service.
10. Open a command prompt as Administrator.
11. Run the following command: Psconfig.exe -cmd upgrade -inplace b2b -wait -force
12. Check the Upgrade Status.