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 found a model for proper reasoning in mathematics, especially in geometry, and his appendix on Geometry was meant to illustrate the effectiveness and usefulness of his method. His method was based on four basic rules for deducing knowledge in the manner of a geometry proof.