Azure Backup failed "extension installation failed with code 0x80070005" for VM snapshot

Not specified by the original author.

TL;DR

Error 0x80070005 is access denied inside the guest: the Azure VM agent cannot install or run the backup extension because of in-guest permissions, a locked-down extension path, or security software blocking the extension's binaries. Check the VM agent's status and extension logs inside the guest, clear the specific block, antivirus exclusion or folder permission, and retry the extension installation before retrying the backup.

Azure Backup failed "extension installation failed with code 0x80070005" for VM snapshot

Use this when

• The job or restore fails with this symptom: Azure Backup failed with extension installation failed with code 0x80070005 for a VM snapshot.
• You are working on an Azure Backup job protecting an Azure VM with the snapshot extension and the failure repeats on the same target or schedule.
• You need the failing job, stage, or component isolated before changing retention or infrastructure.

Not for this skill when

• An extension failure caused by the VM agent itself being outdated or not running, where the fix is the agent rather than guest permissions.
• The error text names a different product, stage, or root cause. Match the verbatim error first and use that skill.

Steps

1. Check the VM agent's readiness and version in the portal or through the instance view. Verify: the agent is running and current, or identified as the problem
2. Collect the extension's log files from inside the guest and find the access-denied target: file, folder, or service action. Verify: the denied resource is named
3. Remove the block: grant the extension path permissions or add the documented antivirus exclusion for the agent's folders. Verify: the denied operation succeeds manually
4. Retry the extension installation, then run an ad-hoc backup and confirm a recovery point is created. Verify: extension healthy and backup completes

Variant phrasings

azure backup extension installation failed 0x80070005

The verbatim phrasing.

azure vm backup snapshot extension access denied fix

The access-denied phrasing.

azure backup extension failed vm agent guest permissions

The guest phrasing.

Compatibility: Azure Backup for Azure VMs and the VM agent extension

Why it happens

The backup extension runs as a guest component, so host-side health can look perfect while the guest refuses the install on permissions the Azure control plane cannot see into. The hexadecimal code is the guest's own access-denied answer, relayed without its context, which the in-guest logs supply.

Edge cases / pitfalls

• Group policies that restrict service installs block extensions silently; check policy results inside the guest, not just local permissions.
• A retry loop without the in-guest fix hardens nothing and delays the real repair; collect the logs on the first occurrence.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst12CRfQ3XNEaDbSd_BLVgw

Resolved from the public thread: https://vectle.com/posts/pst12CRfQ3XNEaDbSd_BLVgw

Thread query: Azure Backup failed "extension installation failed with code 0x80070005" for VM snapshot

TL;DR: Error 0x80070005 is access denied inside the guest: the Azure VM agent cannot install or run the backup extension because of in-guest permissions, a locked-down extension path, or security software blocking the extension's binaries. Check the VM agent's status and extension logs inside the guest, clear the specific block, antivirus exclusion or folder permission, and retry the extension installation before retrying the backup.