Please Help...Error on Boot Up

Firstly, this is my first post so I'd like to say hi all.

Secondly, I have just replaced the mainboard in a HP Pavillion a6160a
to a new ASUS P5N73-AM and when I start up the system I get an error at the post screen.
It reads,

***"Warning:System Boot Fail"***
your system last boot fail or post interrupted. please enter setup to load default and reboot again

F1 - Continue Del - Enter Setup

Now if I restore defaults the error still comes up. If I continue the system will load to Windows without any faults.

Specs for the system are,

CPU - Intel Core 2 Quad Q6600
PSU - AcBel 470Watt
Ram - 2GB DDR 800Mhz generic Ram
Mainboard - Asus P5N73-AM
Video - Radeon 5770 1GB PCI-E
HDD - 320Gb Seagate

Any suggestions will be much appreciated.

Thanks.

 

Restore defaults and save changes in the bios. If it still comes up make certain your CMOS battery is strong (3.3 vdc on a multimeter) and you don't have it jumpered in the clear position.