for the bin?

i have just aquired a 10gig H/D (seagate)i have been assured it was working fine (i have no way of knowing appart from word of mouth)i already have a 5gig installed so i set it to (slave)when i reboot into bios to auto detect H/D i get both pri master and pri slave (not installed)

I then shutdown removed both H/D and put in only the new one and set to pri master,done a reboot into bios and autodetect again(still didnt detect H/D)

anyone any idea as to what is going on,is it for the bin orcan it be another problem somewhere, can it even be that my pc cant run a 10 gig? (5400)