I had to disable Aero ever since I increased my system ram from 6GB to 12GB, because now my computer keeps crashing, whereas before I installed the extra ram, it never, ever, not even once, crashed on me for over a year.
I suspect something to do with one of my graphics cards, as I have two of them
installed, with 3 monitors running, and sometimes a 4th, and before the memory
upgrade, my Aero would constantly switch off if I had an Internet browser
window open, for example. Since the memory upgrade, Windows has not disabled Aero or poped up the message that system resources are low, or something like that. I so far have only crashed when a video has been playing along with some other simultaneous app running, such as Virtual PC, or Internet Explorer, or Movie Maker, and Aero enabled. Since turning Aero off, though its still early days, my computer has not crashed.