I cannot highlight a whole row or column

[fixer]

Inadvertantly, I pushed the wrong button and am now uanable to highlight rows
and columns to delete , insert or even clear them. This condition applies
to eleven spreadsheets in the same folder.

I don't know where to find a remedy for this situation. Please, can
someone help me?

Windows XP Home Edition

 

[mjones]

Inadvertantly, I pushed the wrong button and am now uanable to highlight rows
and columns  to delete , insert or even clear them.  This condition applies
to eleven spreadsheets in the same folder.

I don't know where to find a remedy for this situation.   Please, can
someone  help me?

Windows XP Home Edition

The first thing that I'd check is my hardware/mouse. Then, I'd check
another program like Word is working okay. Then, I'd reboot. Check
back if that doesn't work. Good luck.