About windows 2000

Hi,
I installed windows 2000 prof. on 1.2 GHz system with 810E motherboard and then i replace system hard disk and put it in 1.7 GHz system with 845 motherboard but when i start my w2k prof. it’s gives me blue screen.Why it gives me this blue screen why w2k prof. not automatically detect another system configuration like windows 98 do.
I hope someone got my question.
Regards.
Anurag.