https://wccftech.com/intel-pentium-4-runs-windows-11-while-majority-of-modern-of-intel-amd-cpus-cannot/ > Microsoft has had its fair share of positive and negative experiences with its newest Windows 11 operating system. Everything from having to set particular settings just to run the new OS, to bugs appearing on various devices that were intended to be one-hundred percent compatible with Windows 11. > This new test by Twitter user @Carlos_SM1995 manages to do something that honestly sounds impossible given the current guidelines and compatibility lists created by Microsoft. The user has installed and activated Windows 11—on an Intel Pentium 4 661 CPU, featuring Hyper-Threading,  from fifteen years ago. This chip is not listed on the Microsoft compatible CPU list they created prior to the release of the operating system, making this, technically, incompatible hardware.