mouse hovering seen as double click - how to switch off?

Please can anyone suggest an answer for below on a new toshiba laptop:
Win XP is somehow set up so that it selects files when you pass over them,
and opens them if you leave the mouse hovering. So lots of programs opened
in error.

I vaguely remember switching this type of thing off last time I had a new
PC, but that was 3 years ago...

I've tried control panel , folder options, "click items as follows" :
"single click to open an item. (point to select)." etc., but nothing I do
here fixes it, and anyway the laptop shows the same options set up as a PC
that works normally.
And it doesn't mention the problem where just leaving the mouse to hover is
seen as a double click.

Is this a known option that you switch off with a new PC? I've tried a
google search and failed to find the right words.

Thanks
Keith