Outside any PC:

Outside any PC: To transfer files in a pinch or use an old drive as temporary external storage, use a universal USB drive adapter cable such as one from NewerTech. This type of cable works with ATA and SATA desktop and laptop hard drives, and it's also great for swapping files during a computer upgrade (or meltdown). Another quick and simple alternative is to use a universal docking station like the $60 NewerTech Voyager S2. If you know how to use a toaster, you'll know how to use the Voyager S2.

If you want to use the old drive on a regular basis but you've run out of ports inside your PC, you could add more ports with an upgrade card. But installing the old drive in an external case is an easier option--and as a bonus, you'll then be able to tote the drive between PCs to ferry large files or to add storage to a laptop.

Match the physical size of the drive with the case's specifications, and match the interface too (ATA or SATA). Double-check, as well, that the case will match your drive size in gigabytes; an old case might not recognize all of the available storage in a newer drive. Just as in the desktop installation described above, a SATA drive should work automatically, while you might have to adjust the jumper pin on an ATA drive. The drive case instructions should show you how.