I have a 1TB SATA hard drive in a third-party USB enclosure hooked up to my computer via USB. The drive has become increasingly unreliable, randomly unmounting and remounting in Windows, making strange noises on occasion, and every once in a while making lots of noise and then unmounting, only fixable by powering down the enclosure, waiting a while, then powering it back up again. I am unsure if the hard drive or the enclosure is to blame. The random unmount/remount could be the enclosure, but the strange sounds are likely related to the hard drive.

Given this uncertainty, I want to figure out which of the two items needs to be replaced. However, I do not know of a way to test each item separately since I do not have an extra SATA-to-USB enclosure to test the hard drive with or an extra SATA hard drive to test the enclosure with.

Does anyone know how to figure out what's to blame so that I don't have to replace both unless it is absolutely necessary.