First of all try to findout if this is related to any recent change that you have done on the machine.
Such rendering issues can happen due to display driver? Try with inbox driver if you have installed additional driver for the display card.
Do you see same problem in safe mode or safe mode with networking?
Are you using AERO? if yes, would disabling AERO help?
Try disabling all third party shell extentions using the tool shellexview and test. http://www.nirsoft.net/utils/shexview.html
If you are not using default windows 7 theme change it to that and test?