This just in. Disregard everything I have said thus far. Here's the deal . . .
It occurred to me that my computer was acting like a computer that was completely out of memory. So I went into Task Manager and, guess what . . . 100% CPU usage going on. It turns out that the villain was McAfee, which was using 99% of memory. I uninstalled McAfee (never liked that son of a bitch anyway - too intrusive) and rebooted. (Why, all of a sudden, McAfee decided to hog so much memory on my wife's computer is beyond me. It had never done it before. I have McAfee on my computer and my CPU memory usage runs around 19%.)
Memory usage after doing that? 12%. All that was left to do was to put another anti-virus in there in place of McAfee. That would be Avast! I did some Internet checking on the best anti-virus programs, and Avast! was well toward the top. We'll see. It's my wife's computer, after all, and she doesn't go to high risk Net sites.
Several of you hit on this issue - had I paid attention when you posted it, we would have gotten to the solution a lot sooner.
So - all's well that ends well. Thank you all!
p.s. And to boot, I didn't have to shell out the big bucks to Computer Guy!