Hi Sachin,
Good day. The quickest thing to check is whether Windows is blocking access to the destination folder on the external drive. This is often caused by the folder's permissions rather than the files you're copying.
- Right-click the destination folder on the external hard drive and select Properties.
- Go to Security > Advanced.
- Check the Owner shown at the top. If it isn't your Windows account, select Change next to Owner.
- Enter your Windows account name, select Check Names, then OK.
- Enable Replace owner on subcontainers and objects, then select Apply.
- Try copying the backup files again.
If the error still appears, try creating a new folder directly on the external drive (for example, Backup) and copy the files there. If that works, the original destination folder has a permissions problem.
I hope this helps.
Regards,
Jhun