Microsoft is pushing update KB5021751 to find out how many of its customers are using a version of Office that has reached end of support or will soon be out of support.

No files will be installed on systems that receive this update, but instead it will run once to check if the Microsoft Office installation is outdated or needs an upgrade soon.

Redmond added that no device restart would be required after installing KB5021751 through Windows Update.

The company says the goal is to find out how many customers are still using outdated versions of Office.

However, the advisory does not mention what information the KB5021751 update will check and what will be sent to Microsoft servers.

“This update is intended to help Microsoft identify the number of users running unsupported (or soon to be unsupported) versions of Office, including Office 2013, Office 2010, and Office 2007,” Microsoft explains in a support document published on January 17 and first spotted by desktop modifier.

“This update will run once silently without installing anything on the user’s device.”

Those who do not wish to install this update on their systems can follow these steps:

1. Download and run the “Show or hide updates” troubleshooter from here
2. Click ‘Next’
3. Select update KB5021751
4. Click ‘Next’
5. Restart your device if prompted

While Office 2007 and Office 2010 already reached their end of support years ago (in October 2017 and October 2020), Office 2013 will reach its extended support date later this year, April 11, 2023.

Once a version of Office reaches end of support, Microsoft no longer provides technical support, bug fixes, or security fixes for newly discovered bugs or security vulnerabilities.

Additionally, support content is no longer being updated and most online help content targeting outdated versions of Office is being removed.

Microsoft recommended users of outdated versions of Office download and install a free trial of its suite of Microsoft 365 productivity and security apps.

A Microsoft spokesperson was not immediately available when BleepingComputer reached out earlier today for more information.