Known Issue Rollback (KIR) is a feature of Windows operating systems, introduced by Microsoft, starting with Windows 10, version 2004. This feature is intended to correct possible bugs and errors that occur after a Windows update.

With the Known Issue Rollback (KIR) feature, Microsoft can quickly identify issues with an update and roll back just the part of the update that introduced the bug. In other words, if an update introduces a bug, KIR can only roll back that change, leaving the rest of the update intact. It is a solution that is most often applied to updates that are considered non-critical and can affect millions of computers worldwide.

So, KIR is a tool by which Microsoft can quickly identify problems that arise after an update of Windows operating systems and provide solutions in a short time (a few days or weeks).

How does Known Issue Rollback (KIR) work?

At the heart of the Known Issue Rollback (KIR) tool are four steps through which the problem is identified and fixed:

1. Identification of the problem. When something goes wrong on Windows, the operating system sends error reports to Microsoft. Users can also send feedback when something isn't working. Microsoft teams constantly monitor user feedback and bug reports. If a problem is sufficiently widespread and serious, it is eligible to be corrected with the help of KIR.

2. Creating a rollback (of a solution). Microsoft engineers create a specific rollback for the identified problem and disable from the update only the change that caused the problem, leaving the other components of the update intact.

3. Implementation of rollback. In the next update of the Windows operating system, users will receive this rollback which will correct the problem in the previous update.

4. The definitive fix. After the problem is fixed, Microsoft releases a new update that includes the final fix. Basically, the part of the update that didn't work initially is also included in this update.

Related: Problems for Dual-Boot computers with Windows and Linux after a security update

Known Issue Rollback (KIR) is a very robust tool that helps Microsoft keep Windows stable and reliable. By quickly identifying and fixing problems, KIR contributes to a better user experience of Windows operating systems. However, as I said before, resolution can take days or weeks, and updates that bring major issues, especially security-related ones, are not resolved through KIR.