I have several drives how can i tell which is which

get into BIOS/UEFI and the drives will be listed in order from port1-X, then follow the cables to see where they are plugged in.

The label on top with the drive information on it helps.  

Usually the BIOS will have them identified by their model numbers, So your WD Drives may appear as WD3000GLFS and WD1501FASS, Seagate drives will have an ST2500 or something like that, So as for what i have listed, the WD3000GLFS is a Velociraptor and the WD1501FASS is a 1.5TB disc. The numbers will usually indicate the size of the drive so unless you have identical drives you should be able to identify them that way. otherwise you can identify them by the BIOS and looking at what physical SATA port they are plugged into to get the listing

Thanks, I just need to find the one drive that my computer is telling me It needs to be formatted