NEW BUILD PROBLEM

hi everyone got a problem thats driving me nuts can anyone help?????
just finished new build all cables are connected to where they should be..everthing seems to work now my problem is this the system cannot find the h/d no matter what I do Icant fix this prob...I have a pata h/d..the system is gigabyte tech..dual core processor...twin dvd burners I have been into the cmos and bios screens and made sure of the settings so now I ask you for your help..you may well have an answer that could solve the prob please help if poss thank you all