Over time, it's common practice to replace old hard drives and SSDs as you upgrade to larger and faster drives. Your older drives are most likely gathering dust in a drawer or still connected to your PC but not serving any purpose. When I migrated to a SATA SSD, my hard drive started feeling too slow, even for secondary storage. And when I moved to an NVMe SSD, the tiny SATA SSD was too small to use as extra storage. Both of these drives remained unused for years before I repurposed them, using them for more than just extra storage. If you have a couple of hard drives and slower SSDs lying around, it might be time to put them to use as recovery drives, scratch disks, and test dummies. Even if some of them have minor faults, you can still use them as tools instead of storing data on them.

Use your old SSD as a scratch disk

Relocate excessive writes from your primary SSD

Okay, a scratch disk is technically "storage," but it's much different from using your old SSD for backups, secondary storage, or cold storage. A scratch disk is a dedicated drive used for storing temporary files you don't want on your primary drive. If you work with programs like Photoshop and Premiere Pro, you'll know that these tools tend to store large amounts of temporary project files and cache on your disk. Saving these files on your primary SSD by default can lead to unnecessary writes that can reduce your SSD's lifespan significantly if you're into productivity workloads.

Designating a separate drive for these temporary files not only avoids write amplification on your primary SSD, but also reduces clutter. Plus, your scratch disk, i.e., your old SSD, will be fast enough so as not to hold your workflow back. If you weren't using your old SSD anyway, you probably won't worry about hammering it with excessive writes. Your scratch disk doesn't need to be too large, either — even a 250GB drive will work.

Test risky software or beta updates on it

Keep your primary drive safe

As a tech writer, I have to delve into programs and updates that I wouldn't want to risk on my main drive. If I'm hesitant about testing a PC performance booster, registry cleaner, a beta Windows 11 update, or otherwise questionable software, I can use an old SSD or HDD as a testing ground. Any performance downsides, harmful registry changes, Windows update bugs, or file corruption will occur on my expendable drive. I can simply wipe the drive and start again, something which will be devastating to do on my primary drive. I don't even need an SSD to use as a test dummy; a spinning drive would do just fine. Using your old hard drive to test software and Windows updates is a great way to keep it useful, avoiding the junkyard.

Create a recovery drive

Better safe than sorry

Facing Windows corruption seems like a question of "when" rather than "if." If you've faced the black screen of death or an unbootable Windows installation in the past, you know what I'm talking about. Preparing for the worst is far better than scrambling when the worst actually happens. A recovery drive can bring your PC back from the dead in a matter of minutes. Using your old SSD as a recovery drive is one of the best ways to repurpose it. You can make it a bootable drive that lets you into the Windows Recovery Environment (RE), so you can run Startup Repair, boot into Safe Mode, or run SFC and DISM scans to repair corrupted files.

Alternatively, you can use a tool like Ventoy to install one or more bootable operating systems on your drive, along with some troubleshooting tools to diagnose a failed installation. Ventoy saves you the trouble of creating separate bootable drives for each OS you want to run. Again, you don't need a large SSD for a recovery drive; a 500GB SSD is enough for a few bootable ISOs and diagnostics tools.

Salvage components from HDDs

For the DIY hobbyist

Finally, if your old hard drive has developed too many bad sectors to be used for anything on this list, you can open it up and recover some useful components for DIY projects. Provided you know what you're doing, old HDDs have several nifty knick-knacks that can come in handy if you're the tinkering type. For instance, you can use the strong neodymium magnets inside the drive to create a knife block or hang pictures from the wall. The platters can be used as mirrors or for a makeshift wind chime. Even the motor can be used to make a mini sander, rotary table, or small spindle. You can use the PCB for practising soldering and desoldering, or use the drive enclosure as a personal safe by removing all the screws but one to serve as a hinge.

Your unused HDDs and SSDs are more useful than you think

I used to consider my old, unused drives useless, since using them as extra storage was inefficient and selling them was not worth the effort. However, I've started repurposing them in useful ways that save them from the trash and give them a new life. You can do the same by creating a recovery drive, testing environment, or scratch disk. If nothing else, you can remove the constituent components from a faulty hard drive for your DIY projects.