Hi Dean, it's possible that the blame belongs to a third party: the provider of your graphics card or graphics chipset driver software. When Firefox is incompatible with that software, you can get strange graphical artifacts on the screen. Perhaps a change in Office is also running into that problem?

For Firefox, to bypass these issues, you typically need to disable the hardware acceleration feature. You can do that in the Options dialog:

"3-bar" menu button (or Tools menu) > Options > Advanced

On the "General" mini-tab, uncheck the box for "Use hardware acceleration when available"

That takes effect the next time you exit out of Firefox and start it up again.

I have no idea how to do a similar thing in MS Office.

You might also investigate with your system manufacturer whether they have any updates for your graphics card/chipset.

The problem was fixed. You are implying that system restored rolled back a video driver update and that was not the case. Yes, the problem involved video display, but it does not appear to be a video driver issue.

I posted with the solution so it would be here if someone else had a similar issue. I don't know why you are trying to tell me how to fix something that I stated was fixed.

I'm not saying that using System Restore changed your video drivers. I'm speculating that the MS Office updates might not be compatible with your existing video drivers and that might be why you got weird screen artifacts.

Some Office updates are optional, but if you had to undo security fixes, I think the other possibility is worth exploring to keep Office as secure as possible. That's up to you, and readers of this thread can decide for themselves.