So i just bought Modern Warfare 2 and i installed it right away. as soon as it was finished, i went to play it and it was working fine, except for all the text was all glitchy. I looked up how to fix it on activisions website for customer support and it said that other customers were having the same problem and that i should try reinstalling the game or updating my driver. After reinstalling the game, the problem was not resolved so i decided to update my driver. I have a radeon x1600/1650 series, and when i updated this via AMD.com, my computer's graphics have really slowed down. The internet won't scroll down quickly (it like, refreshs it every scroll or something) and when i try to play MW2, it says 'directx has encountered an unrecoverable error. click the readme for more info' (something along those lines). and now if i try to play World of Warcraft, a popup comes after start it that says 'failed to find a suitable display device. exiting program.' ive tried re-updating the driver, reinstalling the graphics card, and reinstalling directx and nothing seems to work. anyone have any tips?

Did you uninstall the previous ATI/AMD driver before updating?

In not you need to.

Uninstall first then reinstall the latest.