The built-in Windows utility. Running chkdsk /f /r via the Windows Command Prompt scans the file system and physical sectors for errors without needing a boot disk. To help debug this further, let me know:
Modern computers use UEFI settings that block old MS-DOS programs from seeing hard drives or USB files correctly.
Sometimes your bootable USB creates multiple partitions, or the program is hidden inside a specific folder.
In the context of HDD Regenerator, this typically appears in two scenarios:
When to stop and seek professional help