Event ID 57478: "The operating system returned an unusual error while restoring the following file...It is likely that this file is damaged." is reported in the Event Viewer when performing a restore.
Event ID: 57478
Description: The operating system returned an unusual error while restoring the following file...It is likely that this file is damaged.
This event is reported by Backup Exec when it receives an error condition from Windows when attempting to restore a file. CHKDSK should be run on the disk that is targeted for restore. After running CHKDSK, try running the restore job again.
Sometimes, when the file to be restored is very large (several Gigabytes), the server is not be able to allocate enough memory from the system paged pool and therefore the backup fails. Please increase the size and maximum usage of the system paged pool per what shows in the following Microsoft Article:
Backup program is unsuccessful when you back up a large system volume