Just bought a Hercules 3D Prophet 4000XT 64MB PCI video card which has the Kyro chip. My KDS led monitor has no video except a box stating input is "out of range". The input is detected at 84 hrz. The monitor's range is 60 - 70 hrz. The seller says the card is capable of a range from 60 - 85 hrz. He told me to " clear CMOS and change settings in control pannel". I don't know how to clear CMOS. Please advise. Thanks.