Set the software to skip bad sectors if you are dealing with a failing drive.
True SuperCopier 5 can copy locked files and integrates with Windows Explorer. Unity cannot do that due to sandboxing (unless built with [DllImport("kernel32.dll")] for Windows standalone). However, for in-game data, save backups, mod installers, or level duplication, the free async method is sufficient. supercopier 5 unity free
If you're looking for alternative file copying software, some popular options include: Set the software to skip bad sectors if