I have some nice pictures sent me in powerpoint and would like to save them as desktop background, the usual right clickdoes not work, how can i do this please?
You could try opening Powerpoint, selecting the picture, copying, then opening your image editor (eg. Paint) and pasting. Not a technically respected method but would probably work with some good image software.
Rather than double clicking the file, which just starts a presentation, start Powerpoint then choose File...Open... and select the file containing the pictures you want to save. The methods previously mentioned will work then.