Excel- Selecting several cells rather than one?

When you click/select ONE cell in Excel, do more than one get selected?

Apparently, it’s the scroll wheel on your mouse... (more info here)
http://www.computing.net/answers/office/excel-click-1-cell-selects-multiple-update/8691.html

Try this to fix it:

1. Click on scroll wheel (and let go), you’ll get a compass-like 4-arrow symbol. 
2. Without clicking, move the mouse up, down, left, right — your screen will scroll in those directions. 
3. Now press the wheel again to go back to normal mouse mode. 
4. Now left-click a single cell — it should just select ONE cell. If not, try again! (or leave a comment below and I’ll do a Jing video to show you what to look for)