White ring around desktop screen

[RBC]

When logging on today (Saturday, Aug 14, 2021), a white ring appears around my Dell Inspiron 5477 desktop screen, partly obscuring icons.

Tried to reach Dell and Microsoft tech support to no avail - phone recordings ask me to call back during their business hours. I used to be able to get tech support anytime.

I'm running version 21H1, and 2021-08 Cumulative Update for Windows 10 Version 21H1 for 64-based systems (KB5005033) was installed on August 12, 2021.

Can't find anything to diagnose and resolve the problem. Any suggestions?

 

[Bighorn]

Most Desktop monitors have a Menu button with choices to adjust things, maybe something there? Also right-click the desktop and check the Display settings, maybe the resolution of choice is a bit off. I use a KVM with 4 computers and set their resolution to 1440x900, all work good.

 

[RBC]

Thanks Bighorn. Mine is an all-in-one desktop and I don't see any adjustments on the monitor. Tried altering the resolution but didn't get rid of the "ring".

About 4 hours after the ring first appeared, it diminished in width. 5 more hours later, the ring disappeared!

Although I'm glad the "ring" is gone, I'm puzzled when a problem like this mysteriously resolves itself. And who knows if I'll encounter it again.