BIOS Setup Password

I have second hand LGA 775 intel motherboard that has a BIOS setup entry key that I do not know.

I cannot seem to remove this BIOS password, I tried taking the CMOS battery out for long periods of time, but after putting the battery back in and booting up. (pressing F2 to try to enter the BIOS) even though i get the usual error messages about CMOS errors that suggest the battery was out and the board is reset, a message still comes up saying "Setup Entry Key Detected" and it asks me to enter the password. 
The board has an RM bios and I cant seem to find any default password that work either.

What could I do to remove or reset the BIOSsetup entry key? 
Any suggestions would be greatly appreciated 


Reflash the BIOS