SOLVED! Found a way to do it, much like in windows. In Windows you can change the behavior of the double click to a single click by going to control panel, folder options and checking the single click. I wish we could do that on Ubuntu.
But, a doubleclick is a small price to pay NOT to have use windows.
Mary , try googling the question. Puppy Linux is set to single click by default and any Linux can be used either way.