How do I switch between single- and double-click?

Start Explorer (Start, Run, explorer.exe--or press the Win key + E).

From the Tools menu, select Folder Options.

Select the General tab.

In the "Click items as follows" section, select one of the following:
- Single-click to open an item (point to select)
- Double-click to open an item (single-click to select)

If you choose the single-click option, you can also choose when the system will underline titles of objects.

Click OK.