Issue about boot

Dear All ,

I have a problem in my computer regularly , that , suddenly system turns in blue screen , and some stop error and when i restart system dosent start ,, it shows floppy drive error 40 ,,,, then i go to bois and disable the floppy drive , and again after some it repeats same problem blue screen ,,,, and main thing boot first option goes to floppy drive , if i change to cdrom ,, and save it in bios , ,,, again it goes to floppy drive .

and one short beep and long beep continuously ..

Pentium 4 , intel processor 3.00 ,, and ram 1gb . Os - Windows 7 home basic.


regards
riyaz.