Customizing the Start screen
By default, the tiles on the Start screen seem to be randomly placed into groups, but you can group them however you like. To move a tile to a different group, just drag and drop it. To create a new group, drag a tile away from existing groups until you see a vertical bar, then drop the tile.
To move a group to a different location on the Start screen, mouse over the bottom-right corner of the screen and click the − (minus) icon. All of your groups and tiles will minimize to small thumbnails. Right-click a group, then drag and drop it wherever you want it to be.