I’ve had problems with my Toshiba Portege R600 for a few months now where when using it the display will corrupt from time to time. You can see an example of it below.
I’ve been thinking that it had some major hardware issue and was about to replace it. I discovered however that there is a fix for it. Microsoft has documented here about how systems with certain Intel Express chipsets and memory configurations are not symmetric (ie 2 or 4GB of RAM) will have issues. The solution – very simple. Disable the Virtualisation option in the system BIOS and the problem is now gone!!!