Is there a replacement motherboard and CPU that I can purchase/utilize?

The other aspect is that I do not believe the Area-51 R2 shipped with a TPM chip or the ability to enable it in BIOS (assuming you were to install one yourself). That is another requirement for Windows 11. 

@r1crawford 

If the R2 has INTEL PTT in bios under security then the TPM requirement is not an issue. Intel PTT is basically the BIOS alternative to a hardware based TPM 1.2 or newer. Intel PTT works on pretty much every processor/chipset since 4th Gen Core (Haswell) processors were introduced and it even supports Bitlocker. This is because Intel PTT supports all Microsoft requirements for firmware Trusted Platform Module (fTPM) 2.0.  That does not cover the Directx 12 video or 1280 x 720 monitor requirement.

Microsoft has been back pedaling ever since it got the loud and clear message from DOD about requiring TPM 2.0 and 8th gen cpus.

DOD cancelled the multi billion dollar JEDI project over Windows 11, Secure boot required ON and TPM 2.0 required.

The new Hard floor is less aggressive.

Apple's response to Microsoft power grab to control the entire Internet and PC's making windows 10 dead in 2025 is hilarious.

The will now Allow OSX Lion and Mountain Lion to be downloaded free and that means the hackintosh community can help people with older processors use OSX after 2025.

https://www.tonymacx86.com/

UniBeast is a tool that creates a bootable installer out of your downloaded version of macOS. In order to start fresh, you'll need access to a functional computer running OS X Mountain Lion 10.8.5 or later. This is a requirement, as you need access to the Mac App Store to download macOS and create the installation drive.

there are many choices.  look for a standard ATX format motherboard that has 300 series or above intel chipset  since they will support 8th gen or above cpu for Win 11.  As already mentioned look for TPM option in the board.  A popular choice is Z490 board with 10th gen cpu such as that from MSI etc.  The new board must have USB2.0 9 pin connector to be used in R2 case.  The Dell oem board for 8+ gen cpu are mostly proprietary and not suitable for R2 case  For example, the 2-3 year old xps 8930 motherboard and 8th gen cpu does not have USB 2.0 header on board to enable R2 case FIO board connection and LED control.

Area-51 R2 cannot upgrade to any CPU that is within the Windows 11 compatibility requirement.

I'll go with the option of system board replacement and new CPU to be ready.

Being trying to find that MSI board with USB2.0 9 pin connector and R2 compatible (don't want a MLB that's not the right size/fit) to be used, but nothing concrete so far.

I've no issue with swapping out the MLB by myself, but was hoping it'd be a straight forward swap (not requiring additional cables etc as per other posts I've read, as that's where I'd struggle).

Got away from the tech side of things about 8 years ago, and lost these days when it comes to upgrades/compatibility etc (which is why I went with the R2 in the first place).

I have the same system and issue, and was wondering what board and CPU you chose to upgrade to?

Thanks!