Microsoft 365 Apps (Office) are updated differently from most other applications. They are not installed or patched as traditional packages. Instead, updates are handled by Microsoft’s built-in Office Click-to-Run service.
When an update is triggered, we instruct Click-to-Run to check with Microsoft for available updates and apply them if they exist. In most cases, Click-to-Run will download and prepare the updates promptly. However, the final application of those updates is fully controlled by Microsoft.
Because Office applications - most notably Outlook - are often running continuously, updates cannot always be applied completely while the system is in use. This can leave a device in a temporary or partially updated state until the system is restarted. A reboot resolves this in most cases, though not all.
For this reason, we strongly recommend that customers implement a reboot policy to reboot Windows devices a few days after each monthly Patch Tuesday. This ensures that pending updates for Windows, Microsoft 365 Apps, and third-party software can be fully applied.