My solution was to Uninstall the Intel Graphics Driver from my laptop. This of course caused my screen to go blank. I then used the big red button to powerdown the laptop. When I repowered the laptop defaulted to an SVGA driver and W7 hunted for a suitable driver for the Graphic set. When it found these drivers it installed them and rebooted. I now have an almost fully functioning display at 1920*1080 except the task bar has disappeared at the bottom of the screen (by dragging I can make it visible BUT the Windows roundel Start button is half hidden).