fatal exceptions

I am running win 98 se with 96 megs of ram. I keep getting fatal exception which make the (it is now safe to turn off your comp) screen come up. After rebooting all my display setting are changed. Rhey go back to 256 colors and I also have to resizemy desktop. It happens at random times so I can’t say it is a certain program causing it. Any help would be appreciated.
David