OK . . . The JMP Install Checker gave an i a warning on a reboot flag in Registry. I did not save the exact message, but it indicated that a reboot was required. I used Google to search on the warning message, and found some instructions:
Error: "...pending system changes that require a reboot" when installing or upgrading Endpoint Prote...
First I followed up with the Registry Editor.
The "PendingFileRenameOperations" registry entry contains information about files that Windows has marked to replace after restarting the computer.
This entry is located in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SessionManager\
.
. . . If the error persists after you restart the computer, follow these steps: [as was my case]
Then I deleted certain files by going to settings-system-storage. And then I did another reboot. After the reboot, the JMP Install Checker did not give the warning, and also did not open additional home windows.