Casey in Mudville
The answer is:
Control Panel
Mouse
Touchpad
Change touchpad properties
Voila: on-off switch.
Unable to explain why I did not arrive at this easy-to-find place each time I wanted to turn the thing off.
MEANWHILE::
I said to myself, let's just try uninstalling the touchpad and then see if I can get back in there and reinstall it using the touch screen on the laptop.
Uninstalled it.
It said I had to reboot. Did.
It stuck in the reboot, saying there was a problem, and should it fix itself by returning to a previous working status.
First I told it no, and it came back to the same place. I told it yes.
It booted up and began behaving erratically. (The touchpad, BTW, was now working again).
Blue "thinking" circle appeared permanently with the cursor. Cursor was iffy in operation.
Called up Dell. Nice lady got remote control. First she couldn't see the cursor at all. Finally ran hardware diagnostic, no problems, looked around some more and told me she could fix the problem for $110, or do a year's additional warranty for $240. I declined both. Paid ?$500 for the whole computer. She kindly gave me the key to disabling the touchpad, and we parted company.
I rebooted and started to report all this here. Cursor got weird but mostly immobile. Then Firefox became Not Responding and stayed that way. Trying another reboot, but have retreated to the desktop.
Now I really need help. Perhaps you will redirect me to the correct department.
I take note that it would be CHURLISH of me not to make a donation to WTT under these circs!
BTT, Firefox has done some NR previously.
Think the computer really did not like my uninstalling the TP, but I don't know why.
denno