What does Windows error code 4004 (ERROR_FULL_BACKUP) mean?

ERROR_FULL_BACKUP

The backup failed. Check the directory to which you are backing the database.

ERROR_FULL_BACKUP is Win32 error 4004 (0xFA4) and belongs to WINS full database backup.

Where the result appears

• Manual full WINS backup.
• Scheduled protection of the legacy name database.
• Pre-migration backup before removing a WINS server.
• Recovery testing on a standby server.

Likely causes

• the destination directory is missing, inaccessible, or full.
• the WINS service account cannot create or replace backup files.
• storage or antivirus interference blocks a consistent database copy.
• the target contains incompatible or locked backup artifacts.

Troubleshooting steps

• Record exact destination path and volume free space.
• Record ACLs as evaluated for the WINS service identity.
• Record filesystem and antivirus events.
• Record existing backup file names and locks.
• Record WINS service events at backup start and failure.

What to verify

Verify whether the destination directory is missing, inaccessible, or full. Check exact destination path and volume free space together with ACLs as evaluated for the WINS service identity.

Handling, retry, and recovery

Correct the destination problem, use a local supported path, and repeat a full backup. Verify the resulting files and test restoration before relying on the backup.

Difference from nearby codes

It means creation of a full backup failed; it does not imply that the active WINS database is already corrupt.

Practical example

A backup target moves to a new volume whose ACL excludes the service account.

References

• Microsoft: System Error Codes (4000–5999) — reference for error 4004.
• Microsoft: Windows Internet Name Service (WINS) — reference for error 4004.
• Microsoft: WINS Management Protocol — reference for error 4004.