What’s the Best Way to Back Up 25 Computers for Long-Term Storage?

For legal purposes, I'd recommend removing the drives entirely and tagging them with the owner's info. If you need them operational, just clone the drives and put the clones back into the computers.

Have you thought about using Clonezilla? It's a straightforward cloning tool. If you want an even simpler solution, you could just remove the SSD drives and store them safely on a shelf—no need for fancy software if you just need to keep them.

If you don't have to restore these as working computers, you might want to look into using the .wim format. It allows you to store multiple images with deduplication, which saves space on a file server. You can use ImageX to append the C: drives into one WIM file, making it more efficient for storage, especially for legal holds.

If pulling the drives isn't an option, maybe give Disk2vhd a try. It’s a handy tool that creates a VHD you can mount later—it gives you flexibility without having to remove hardware.

If you're mainly backing up data instead of entire systems, consider just transferring the essential files to an external hard drive or using something like AWS cold storage. It could save you a lot of hassle!