The following points explain my problem:-
1. when i switch on my pc ,it asus motherboard logo freezes for about 40-45 secs, then it says "unknown cpu detected , update bios to unleash full power. press f1 to resume..."
2. after that it seems to be normal, i,ve attached a file to explain the problem
3 cpu - intel core 2 duo E7300 2.66 ghz
motherboard - asus P5B- VM SE
[recovering disk space - old attachment deleted by admin]