If you need to use Windows 8.1 or an older version of Office without paying for a retail license, consider these legitimate options instead of Microsoft Toolkit:

Microsoft Toolkit 2.5 Beta 5 is an unauthorized third-party tool primarily used for the bypass-activation of Windows 8.1 and various Microsoft Office versions

This article provides a deep dive into what Microsoft Toolkit 2.5 Beta 5 is, how it supposedly works, the risks involved, and why you see this keyword populating tech support threads.

developed or endorsed by Microsoft. Using it violates Microsoft’s Terms of Use. Security Risks