VERY WEIRD keyboard Presario problem
 

A few months ago a friend gave me a "dead" compaq presario 1200-xl-103 notebook for my experiences with Linux. The problem was the motherboard, so i disassembled it and after a few more months i found a compatible motherboard at "e-bay". I assembled the machine, turned it on and it worked.
After a few seconds i found out that the keyboard was all misplaced, that is, if i pressed "i" it would give me "z". The problem is not OS dependent, and it comes right on the BIOS because the keys are all discrambled from the start. The usual setup key is "F10" and now it works on "F7", and it seems that the only key working on the right spot is "RETURN". Phisically the keyboard is working correctly, so the problem may only be software dependent. I managed to enter setup trough the new "F7" setup key but the bios has no option to alter the keyboard layout.
I tried an external PS/2 keyboard and it works flawlessly.

The question is:
a)The keyboard as a portuguese layout, but the motherboard came from US, is this why??
b)How can i fix this?? I do not have the original cds. Is the any software that i can use to reprogram the keyboard layout??
c)Can this be a deffective keyboard?? Not pluged rigth??

Thanks for your help