I've not even done any sort of gaming, just messing about on the internet and I've gotten 2 notices that my ATI display driver has crashed. I just installed my GPU today (MSI Radeon HD 7770 GHz Edition). I ran the disk and did the driver installs, etc. Then now (tonight) I've noticed the 2 crashes.
Go to control panel and remove the drivers you installed. It is likely you have some left over drivers from your old card that are causing problems. To make sure you remove all video card drivers from your computer I would recommend a program like Drivesweeper. After that go head and install new drivers. Make sure you are using up to date drivers. AMD drivers have come along way in recent months and who knows how old the drivers that came with your card are. If you are uncertain about which drivers to install AMD has a small program that will automatically do it for you. Hope this helps