Nan, I am impressed at how PC savvy you seem to be.
I always liked MalwareBytes to scan for malware when I had PCs. It's free and that may be what you are using. Malware is usually the prime suspect when a PC suddenly starts running slow, although sometimes a fragmented or full disc drive can be a problem. How much disc space do you have?
Plenty of space. Have the system set to defrag once a month, whether I need it or not, in the middle of the night.
I've got 725 gig free of 916, so I don't think space is an issue.
I went into the command prompt to see what devices were set to allow them to wake the system, and both the mouse and the keyboard were there. SO, it's not that....
And I wish I was. (Computer savvy.) Forty years ago I was well-entrenched in a career as a large-scale IBM mainframe systems operator running IBM 360, 370, and, I think, 4331.... Took time off to have a kid and ~bam~ too obsolete to go back. (Plus I couldn't find rotating shifts daycare. And those types of jobs are rare now. Which is too bad, as I'd go back and do one of those again in a heartbeat. I loved that job!) And now I have to get the Daughter to show me how to do things on the computer! (arrrgh!)
EDIT: Holy Frijoles Chrome is a memory hog! I've been using the Avast browser, on the Daughter's advice. It's a modified Chrome browser. That, apparently sets up a process for each open tab you've got and then holds it in memory, or some such. The Daughter is really bad about using my PC and leaving like 10 or 12 tabs open when she calls it quits for the night. Just in case that's part of the problem, I'm going back to Firefox. I guess we'll see how it goes in the morning.