• Contact your motherboard manufacturer to see if upgrading your bios is necessary. In many instances, upgrading the bios is necessary in order to enable support for new products.
• Verify that the motherboard is installed correctly and is not shorting out on the underside of the chassis.
• Verify the memory modules are the correct match for your motherboard and that they are seated properly.
• Verify that all add-in cards are seated properly.
• If your PC uses a Boxed Intel® Desktop Processor in the LGA775 or LGA1366 package, be sure the heatsink is properly installed and 'locked'. Pay particular attention to the proper orientation of the locking pins and give a good push down on the pins (sounds like a double click) to lock them into place. Rather than locking the fasteners in a circular fashion, it may be helpful to alternate locking the fasteners.
• If the Intel® boxed processor heatsink has been previously installed, make sure all fastener slots have been reset to factory default by aligning each fastener notch to be perpendicular to the heatsink.
• Verify the chassis/case and power supply are appropriate for the processor model and the motherboard you are using.
• Verify that the thermal solution is adequate for the processor and frequency of the processor.
• Make sure the processor fan cable is connected to the correct fan header (specifically for the processor). Refer to your motherboard documentation for more information.
• Make sure that the thermal interface material or the thermal grease is applied to the processor properly.

This applies to:

Intel® Core™ i5 Processor Intel® Core™ i7 Processor Intel® Core™ i7 Processor Extreme Edition Intel® Core™2 Duo Desktop Processor Intel® Core™2 Extreme Processor Intel® Core™2 Quad Processor