Thanks to Dr Dave - Reloaded, the problem has been solved!! WoooHooo!!
Seems that I left a crucial bit of info out of my original post on this topic, one that might have saved a whole lot of grief, and repair suggestions that may not have been necessary.
The crucial bit of info?
What was I doing when the system crashed. Duh. . .
The old computer (a Dell 4550) froze when I sent a document to be printed from the new computer (a Dell 9200) over my home network to a printer that was connected to the 4550.
Dr Dave, in a PM, made a suggestion that triggered the repair, outlined as follows:
From the near-frozen desktop, use Ctrl+Alt+Del to get to the Task Manager. Tab to "Performance". Discovered 100% of CPU was being used - strange. . . Tabbed to "Processes", and found a file called spoolsv.exe
to be utilizing 98 - 99 of the CPU. Tabbed down to that file, and deleted it. Within a few seconds, the mouse began operating. Progress!!
From there, went into Control Panel and deleted all the printers. Then did a search for "spoolsv.exe", and found it in Windows/System32. Opened it, and, altho all the printers had been deleted, there were SIX print jobs listed in this file. Deleted all six, closed program, shut down machine, then did a cold boot.
System booted normally, mouse worked, keyboard response was back to normal. Everything was just like it was before the freeze. WoooHooo!!
Did a Google search for spoolsv.exe, and discovered that it's the print spooler, and yes, it's prone to either freezing the machine, or making it terribly sluggish - exactly what happened to me. It can also be a trojan, and if so, it will be found in another folder somewhere. May also have a slightly different spelling, too.
So, my hat's off to Dr Dave, as well as to everyone else who scratched their heads over this with me. I sincerely appreciate the help from each and every one of you.
And yes, I'm in the process of backing everything up!!
Now back to our regularly scheduled busnut ramblings. . .