ATI 1150 3D GRAPHICS DISPLAY PROBLEM

Hello,

I have a dell Inspiron 1501 Laptop, and I recently upgraded it to windows 7.  There weren't any drivers for the windows 7 so the system told me that I can use windows vista drivers.  However, I downloaded and installed the ATI drivers and also went a website and downloaded the recent ATI Drivers as well, but the ATI Drivers keeps on shutting down and restarting each time I go to a fullscreen mode on any movies that I'm watching.  In other words, it's constantly shutting down and restarting, but especially when I go in fullscreen mode if I'm watching a movie off the internet.  Can anyone help me with this issue please?  Thanks.