Thank you for your help. Did not find VGA cards mentioned, per se. Found "Display adapters": ATI Radeon HD 3450. Is that the same thing? Accidently found if I scoot the arrow on the wrong left monitor, hard left; it jumps back on the right side of the right monitor--a big help. Still the accidental changes are annoying. Still prefer a mouse with three-position rocker lever, left down to left monitor, right down to right monitor, spring loaded to neutral center position of either neither monitor, or wherever it happens to be.
I hate to loose you. Please transfer this question to the proper forum: I keep getting "Low Disk Space, back-up disk D full". I've backed up now on an external (but connected) drive. How can I clear D. I've tried many times, but the deleting unnecessary files instructions delete nothing?