Leo from UK writes: How can I change my mouse to single click, please?

Leo, since you asked so nicely, here you go.

Open your Start Menu and type in Folder Options.

 Folder Options should be your top result, click on the icon.

A window will open where you’ll have the option to switch to single-click.  Select single-click to open an item and don’t forget to apply the changes.

~ Cynthia