Inactive copy of Outlook OST will not back up

3+GB Outlook .OST file will not back up (error: “these files failed to back up”). To confirm this file was not just blocked because it was in use - made a second copy of that OST file and the inactive copy will also not back up. The external drive is formatted NTFS and connected via USB. Latest version WDBackup installed. Windows 10. Thoughts?

Hi there,

Please know, WD Backup will not backup files that are locked or in use by the Windows operating system, running software, programs or processes.