View the Use of Third-Party Software or Websites disclaimer.
Western Digital Support cannot help with third-party software or hardware.
Files skipped or not backed up can be caused by a few things including the backup software.
The most common causes are:
Bad Cables
Make sure all cables are tight and not loose. Use a known good cables.Solution: Replace the cables.
Computer System Files
These files are part of the Operating System (OS).
They are write protected to prevent accidental deletion or changes.
File level backup software may exclude these files.
Solution: Image backups should be used to backup the OS.
Exclude "C:\WINDOWS" and "C:\Program Files" from the backup job.
The process cannot access the file because it is being used by another process.
(Exception from HRESULT: 0x80070020)
File In Use
The software may be trying to back up a files that is open or in use.Solution: Save and close open files.
Try not to open files while the backup is running.
The process cannot access the file because it is being used by another process.
(Exception from HRESULT: 0x80070020)
CPU and Memory
Memory and CPU usage can cause a backup to fail or not complete.
Solution: Check the computer CPU and memory usage while the backup is running.
Upgrade the drive to SSD, CPU and memory if close to or near 100%.
- Windows
Microsoft Support Article: How to use Windows 10 Task Manager to monitor system performance
- macOS
Apple Article: Activity Monitor User Guide
Fragmented Disk
Defragmentation occurs to disk over time by adding, deleting of files, and web browser caching.
Solution: Degrag, check and repair the drive.
- Windows
Microsoft Article: Run the System File Checker tool.
Microsoft Article: Defragment your Windows 10 PC.
Microsoft Article: Use the System File Checker tool to repair missing or corrupted system files. - macOS
Apple Article: How to repair a Mac disk with Disk Utility.
Drive Failure
The drive may have bad sectors and failing.
Solution: Check the drive for errors.
- Internal Drive
Answer ID 31759: Download, Install, Test Drive and Update Firmware Using Western Digital Dashboard - External Drive
Answer ID 50396: How to Install and Use WD Drive Utilities Software
Infected Computer
A computer infected with a Virus or Malware can prevent a file from being backed up.
Solution: Check and remove any Virus or Malware free.
File Permissions
Operating Systems set permissions and rights to folders and files.
They control the ability to view, modify, change, and delete files.
Solution: Ensure the owner and system have permissions to access the files.
Contact the Microsoft or Apple for information about how to verify file permissions, and take ownership of files.
Long Filename or Folder Paths Too Long
File names and folder paths may be too long.
The maximum length of a pathname is 256 characters. That includes parent directories, child directories, and the file name.
The backup software will attempt replicate the path when creating a backup destination path.
Solution: Omit the directory from the backup job. Shorten the folder and file names.
Special Characters
Do not use reserved characters in folders or file names.
- < (less than)
- > (greater than)
- : (colon)
- ' (double quote)
- / (forward slash)
- \ (backslash)
- | (vertical bar or pipe)
- ? (question mark)
- * (asterisk)
Need more help?
Microsoft Article: Naming Files, Paths, and Namespaces.
Sleep and Standby Modes
Computers that go to sleep or standby mode will cause the backup job to stop.
Solution: Prevent it from going to sleep or standby. Keep the screen from locking.
