You say "the comp doesn't detect the drive", but don't tell us what info you have. If this is based only on looking in My Computer, then I'll bet takerudavis is right.
Any blank new hard drive has to be prepared for use by Windows; until that is done, Windows will NOT show it in My Computer. The preparation is two steps: create on it at least one Partition (this defines how its space is used in one or more volumes treated each as separate drives, and sets up the disk's master Partition Table to keep track), and Format each such Partition to install a file system to keep track of all the files. Both can be done using Windows' built-in tools in Disk Manager but you need to learn a little bit on how to use them. Even easier is software utilities that you can get for free from your disk's manufacturer. Sometimes these are on a CD that came with the disk. Sometimes you need to go to the manufacturer's website and download the free utility package. Either way the utilities simply make this job simpler than doing it yourself in Disk Manager. But it's not that difficult, anyway.