Some HDD makers have very good diagnostic test utilities available for free download on their website. In most cases, though, these tools will ONLY test a HDD made by that company. Two I know of are Seagate's Seatools, and WD's DataGuard. In each of those there are some simpler quick tests and some long complete tests. Some of the tests and some of the repair tools they include are destructive to existing data, but they warn you and ask for confirmation before proceeding. In your case, I'd guess there are no data you want to protect anyway. They also may include a zero-fill utility which is a very good way to ensure the HDD has no old data on it and, more importantly, that every disk sector is tested and all poor sectors are replaced with good ones before you use the HDD.