Cannot deselect rows and columns

[Guest]

When opening a new worksheet or an excisting worksheet and I select a row and
move the mouse, all rows are columns are selected and cannot deselect them.
The other worksheets cannot be used because the mouse becomes disabled.
Tried to do repair, started excel in safe mode, deleted excel entries from
registry but not a go. Is anyone with the same problem.
Thank you.

 

[Guest]

I solved the problem.
I just opened the original file that began the problem. Deselected whatever
was selected. Closed. Opened new file or existing file. The autoselection
problem is gone.