Reset the CMOS.  It is often helpful to reset them first after installing new hardware.  Check your motherboard's manual for instructions. 

Also consider updating the BIOS if resetting the CMOS doesn't help. 

Your full system specifications? 

No - check your motherboard manual:

Resetting CMOS is done on the motherboard itself, not on the BIOS interface

The CMOS jumper is on the part marked 'V':



http://www.intel.com/content/www/us/en/sup.../000021070.html

Turn off your PC, and unplug from its socket.  Then move the jumper block from 1, 2 to 2, 3, as shown:





Once finished, reconnect the power and turn the PC on.  You'll see a configuration menu, and press F9 to reset the BIOS to factory defaults. 

If the machine boots normally, then turn off the PC and disconnect the power.  After disconnecting the power, move the jumper back into the original position.