I've got the 9700 pro in my Dell 3.02 ghz 8250. Anyway everything's been fine for just over 2 years - suddenly the other night I turn off the computer and lines appear on the screen. Now, particularly if the hard drive isn't whirring the screen remains ok but when the hard drive starts doing some things I get on screen problems. Sometimes like this... Sometimes like this.... When I try to play any game it quickly goes like this..... I don't think it's anything to do with overheating because sometimes it is messing up as soon as switching on while at other times the PC has been on for some time and everything's ok. Any help would be greatly appreciated.