How to clear screen artifacts without rebooting Windows (multiple versions)

go to control panel | display and change the screen resolution. the artifact will go away. click on cancel when windows asks you if you want to keep the new resolution. this works on laptops too.

I occasionally get screen artifacts like this in Windows 8.1:

that hover above anything, including the Start screen and above the Snipping tool preview. (Rectangular Snip is a menu from the Snipping Tool, now hovering over Outlook.)

I locked my computer and unlocked it, which removed the artifact.

Edit: I don't know why, but just using Chrome for a few seconds also removes the artifacts.

At work. Windows 7 Enterprise SP1 (32bit). Intel i5-2400S CPU @ 2.50GHz. 4GB RAM. Intel Graphics Card.

For me, I went to Screen Resolution/Advanced Settings. That got me the Generic PnP Monitor and Intel HD Graphics properties dialog.

On the MONITOR tab, I changed the Colors FROM True Color (32bit) TO High Color (16bit). That did it. I then returned to True Color (32bit) and the artifacts remain gone. I figured changing the color would not change the placement of anything on my screen. I would have tried the Refresh Rate but mine only has a single 60 Hertz.

The artifact was replicating across all 4 of my virtual desktops. This allowed me to keep all of my: 5 apps in SysTray, 22 Taskbar apps in DT1, 5 in DT2, 13 in DT3, and DT4 is my overflow for really-temp work so it had 0 at the time.