This is currently the most popular community resource for historical software. You can find "fully updated" versions uploaded by users that include security rollups through early 2023.
that includes updates up to June 2022 and .NET Framework 4.8. Windows 8.1 x64 (176 Updates Preinstalled) Internet Archive windows 8.1 fully updated iso
If you combine:
The quest for a is one of digital preservation. With Microsoft’s official servers no longer optimized for this OS, the responsibility falls to the user community and technicians. This is currently the most popular community resource
Before diving into the technical details, it is vital to understand the lifecycle of Windows 8.1. windows 8.1 fully updated iso