Hazy Hazy Black

I've had a problem recently come up: I have Windows 7 64 bit, and sometimes when I try to open Mozilla Firefox, or try to open a hyperlink in MS Outlook, after a couple of minutes the programs lock up and say "Not Responding" and/or a white haze appears over the program. When I ctrl-alt-del the same thing happens...black screen and then the same
error message telling me the log-in failed and I might want to turn the computer off using the power button.