They are where you stored them, it's as simple as that. Or, if you have a backup on a different medium (some people don't backup their data, can you imagine that?) they are there.

However, Windows respects ownership. The two common options to access them on their original location are:
1. Boot to a Linux disc or stick (free to make) and copy those files to a FAT32 formatted device (disk or USB-stick).
2. Take ownership of the Users folder (if you stored them there). https://www.google.com/search?q=windows+10+take+ownership+of+folder tells how to do that.