2. Click on Change PC Settings.  Then click on Personalize in the left pane. 3. In the right pane, click on Lock screen and then Browse to find your desired image. When you find the image you want, highlight the file by clicking on it, and then click on Choose Picture in the lower right-hand corner.
RenÃ© Descartes, (born March 31, 1596, La Haye, Touraine, Franceâdied February 11, 1650, Stockholm, Sweden), French mathematician, scientist, and philosopher.
Descartes's Method of Doubt. Descartes thought that we could achieve absolute certainty by starting with radical doubt. He adopts this strategy in the Meditations on First Philosophy, where he raises sweeping doubts with the famous dream argument and the hypothesis of an evil demon.