Windows 11 Version 23H2 Hardware Requirements and Recommendations

Windows 11 has stricter hardware compatibility requirements than its predecessor, the first time that's been true since the 2006 release of Windows Vista. And these requirements artificially limit which PCs can be upgraded from Windows 10.

Additionally, certain Windows 11 features require additional hardware capabilities. This, at least, is reasonable.
Understand the Windows 11 hardware requirements
To upgrade to Windows 11, your PC must include:

A compatible microprocessor. Windows 11 requires a 64-bit 1 GHz or faster microprocessor or a System on a Chip (SOC) with two processor cores or more. But not any processor will do: Instead, Windows 11 only supports very specific, newer microprocessors. Generally speaking, this means an 8th Gen Intel Core processor (or its AMD equivalent) or newer, which dates back to late 2017. Regardless, we recommend the newest and fastest microprocessor you can afford.

RAM. 4 GB or more. We recommend 16 GB of RAM or more.

Storage. 64 GB or more. We recommend 256 GB or more of SSD (solid-state drive) storage or more.

Firmware. UEFI (Unified Extensible Firmware Interface) with Secure Boot enabled.

Trusted Platform Module (TPM) version 2.0. This is a hardware-based security solution and it was the subject of much consternation for enthusiasts when Windows 11 first debuted in 2021. That said, TPM 2.0 chipsets have been broadly available in PCs for many years.

Graphics. DirectX 12 or newer compatibility with a WDDM (Windows Display Driver Model) 2.0 driver. This compatibility is common today and will pose no issues for almost any PC.

Display. HD (720p) or higher with a physical size of at least 9-inches (diagonally), with 8-bits per color channel. We recommend a Full HD+ (1920 x 1200) or higher resolution display with a 16:10 aspect ratio as a more reasonable baseline, and a 4K+ display (3840 x 2400) or better is a noticeable improvement.
Find out if your Windows 10 PC can upgrade to Windows 11
If some of the information in the previous section is confusing, no worries: Microsoft offers an app called PC Health Check that will examine your PC and tell you whether it's compatible with Windows 11. If it isn't, PC Health Check will explain why.
If your Windows 10-based PC is up-to-date, Microsoft will have installed PC Health Check on it already, so you can use Search in the Taskbar or Start menu to find and run the app.

PC Health Check is straightforward: Simply select the "Check now" button to see whether your PC meets Windows 11's hardware requirements. If it does, you will be told so.

What if your PC is not compatible?
Depending on what the PC Health Check app reports, you will have some choices to make. Some requirements, like Secure Boot and TPM 2.0 may in fact be present in your PC but not enabled, so it may be worth visiting the system firmware to see whether you can enable them

In other cases, you may have to buy a new PC. Or, if you are technical enough, you can follow...