To recover deleted files from a hard drive, you should first stop using the affected drive. Download and install Disk Drill on a separate drive, then select and scan the hard drive for lost or deleted data. Refine the results using filters and categories, preview the files, and recover the ones you want. If you’re dealing with an inaccessible or unresponsive drive, consider creating a byte-to-byte backup and scanning that instead. For drives suffering from physical damage or failed recovery attempts, consult a professional data recovery service.