As I explained in your previous thread:
passport-external-drive-bad-sector-t21476.htmlmy experience of that error message is that Windows believes the drive is still being accessed. Specifically a process (not necessarily a visible application, but it could be a Windows service or other background process which is not listed in the Task Manager) has an open file handle to the drive or a file on the drive.
This is a Windows sys admin challenge, to find the cause on your specific PC, and so I expect you'll find better sources of Windows support elsewhere. Personally, I'd start by using the SysInternals "Handle" utility to look at the list of open file handles listed by process (PID), but I'm not offering to support that utility remotely.