well this is my 3rd instsall of windows 7, each time a new problem arises, this time its the DWM.exe process,
it seems that randomly it spikes to 25% cpu and everything judders, the mouse stops working properly, the lights on my USB mouse go off and on, and its really annoying, im running virus checkers on it now
at this rate im going to reinstall vista, for all its faults, ive never had any major issues with it!
As it's a new problem then I doubt it's a graphics card driver. Dwm manages the aero, live task bar thumbnails and flip. (Win key + Tab). Try task manager then right click dwm.exe and click end process. It will restart automatically. See what happens. Priority is set to high.