Try not OCing your computer to see if it boots OK. Reset the BIOS to default. From your second question I gather you are not very familiar with OCing. Some changes can screw up your computer.
To increase your bus speed you need to change your CPU Host Frequency from the default of 266 to something higher. These are the stock settings...
http://www.legitreviews.com/images/r...2duo_e7200.jpg