Error 0x80070015

How to Fix Windows Defender / Backup Error 0x80070015 (Drive Not Ready)

Fix time: 15 mins Difficulty: Medium 0 views Updated: July 2026

Solve device validation errors and scan blockages showing code 0x80070015.

Symptoms

Windows Defender offline scan fails with error 0x80070015

Common Causes

Disconnected external drives assigned to update or scan targets

Step-by-Step Solutions

Method 1: Clear Windows Defender Registry Cache

Navigate to HKLM\SOFTWARE\Microsoft\Windows Defender\Scan in Registry Editor.
Delete historical target keys pointing to inactive external media paths.

Frequently Asked Questions

Make sure your target external backup drive is plugged in and powered.