Manage patches for Windows devices
The patch engine scans each Windows device and lists the operating system updates it finds. Patches don't install until you install them yourself or a patch policy approves them. Each patch has a classification that describes what kind of update it is. Use classifications to filter the patch list and to set approvals in a patch policy.
For detailed steps on installing patches, see Manage patches for devices. To decline patches, see Decline or reinstate patches.
- The device downloads a Windows patch before it installs it. Large patches, such as upgrades, can take a long time to download.
- Some patches don't need a restart, but you can still choose to restart the device.
Windows patch classifications
Classifications for Windows OS patches come from Microsoft. Third-party application updates appear under their own Applications classification, not a Windows classification. For details, see Manage third-party patches for Windows devices
Windows OS patches use the following classifications:
- Critical Updates
- Fixes for specific, widely released problems that affect how Windows works, and that aren't security related.
- Security Updates
- Fixes for security vulnerabilities in a Microsoft product. Microsoft rates each one by severity.
- Definition Updates
- Updates to the detection data that a product uses, such as the security intelligence updates for Microsoft Defender Antivirus. These are released often.
Because definition updates are released very often, consider approving them automatically in a policy, or declining them if another tool manages them.
- Drivers
- Software that controls how Windows communicates with hardware devices.
- Update Rollups
- A tested set of fixes and updates packaged together for easy deployment.
- Updates
- Fixes for specific, widely released problems that aren't critical or security related.
- Service Packs
- A tested, cumulative set of fixes released since the product came out.
- Feature Packs
- New product features that are released outside a full product release.
- Upgrades
- Updates that move a device to a new version of Windows, such as a Windows 11 feature update. These can be large and usually need a restart.
Upgrades and feature updates can be several gigabytes and may take a long time to download. Schedule them for a maintenance window.
- Tools
- Utilities or features that help complete a task.