You may need to remove it from the raid array in bios or via the winblows interface as it may be auto adding the sata ports. If the drive has been preformatted for a raid or attempted to have been formatted, especially via a raid prog or bios, it may then read as a bad drive when you try to get winblows to format it. Many other potential answers but that's one I have come across with HPs and other similar systems designed for office(idiot) use (bosses).