hmm, u have almost same specs as mine

. tell me about hard drives?
IDE or S-ATA?
how many?
else Optical Drives.
for Fan thingi, check if it doesnt as well shows up in BIOS settings (power controls - I Believe)
is your OPtical Drive Detected?
and are you using thin line cables on ur hard drives ot thick lines?
have you tested your hard drives on some other PC?
as well check the power connctors on the hard drives, exchange with others so see if they arent culprit.
lastly, have u updated your BIOS?