RE: M4800 and Optimus?
Well, I have now wasted 1 day on this and found that it is perfectly to install the new Nvidia driver without first installing the Intel driver (as suggested by Dell). The fact is you cannot install the Intel driver as the discrete GPU of the K2100M is disabling the HD 4600 card just by being installed and hence will the Intel driver fail by "No minimum .. bla bla bla." simply because it cannot see the card. Anyhow, I found that my graphical issue went away after disabling the Aero Theme and selecting Windows 7 Basic Theme - all suddenly was fast and responsive and much sharper and cleaner. Gosh ! Was just 1 min away from sending the machine back. Now all is perfect - wonderful 3200x1800 screen.