Okay, I have the File settings under Options : Advanced and then Reading Pane set thusly: Mark items as read when viewed in the Reading Pane :: WAIT 0 (ZERO) seconds before marking item as read IS CHECKED

Mark item as read when selection changes IS NOT CHECKED

Single Key reading using space bar IS CHECKED

For a long time after I receive an email and click on it the From/Subject/Received line for the appropriate email remains emboldened and will not mark as read.  Even after I change to another email that one too does not automatically mark as read.

Then for no reason whatsoever, a message marked read and which was manually set as read by the radio button will revert to unread status unprovoked. 

Why does this happen?  I recently had to reload the Windows Office 2013 suite owing to a system glitch. 

and ever since I have felt uneasy about Outlook in particular.  It is disconcerting. 

Please address and advise.  Thank you.  

Hi,

I suspect the View has corrupted based on the description, please start Outlook with the switch "cleanviews":

Press Win + R, type "outlook.exe /cleanviews" in the blank box, press Enter.

Outlook will restore default views and all custom views that you created will be lost.

Then check whether the issue persists.

Anyway, are you using any 3rd-party add-ins in Outlook? Let's start Outlook in Safe Mode to see whether it's add-ins related:

Press Win + R, type "outlook.exe /safe" in the blank box, press Enter.

If there's no issue in Outlook Safe Mode, disable the suspicious add-ins to verify which one caused the issue.

Regards,