Processor Intel(R) Xeon(R) CPU E5-1660 0 @ 3.30GHz 3.30 GHz Installed

[MHGUIDRY]

How can I upgrade this Z420 to support Windows 11?

Processor Intel(R) Xeon(R) CPU E5-1660 0 @ 3.30GHz 3.30 GHz
Installed RAM 64.0 GB
Storage 1.82 TB HDD ATA ST2000NM0024-1HT
Graphics Card NVIDIA GeForce GTX 980 (4 GB)
Device ID 5627A280-680C-46C3-A76C-D0FA9F9F95CC
Product ID 00330-54939-72004-AAOEM
System Type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display

[NonSequitur777]

@MHGUIDRY,

Welcome to our HP Community forum!

There are a number of reliable and effective methods developed which would allow you to almost effortlessly upgrade your so-called "unsupported device" to Windows 11, such as this easy-to-follow YouTube instructional video shows: https://www.youtube.com/watch?v=lSrmhhigEhY&t=332s&ab_channel=Tips2Fix.

This method uses a clever Microsoft (Server) backdoor Windows 11 install method.

This works great: I have used it myself on a number of legacy HP desktops without any issues whatsoever -including an HP Z420 Workstation, as you can see here: Solved: Upgrading an HP Z420 Workstation (v2 motherboard) - HP Support Community - 9373457.

I cannot emphasize enough that this particular W11 upgrade method is hard to beat in terms of simplicity!

The Tips2Fix approach basically modifies the Windows 11 install media by replacing just one file (appraiserres.dll) with the Windows 10 version, which instantly disables all TPM, CPU, and Secure Boot checks without extra prompts or tool-specific steps.

Compared to Rufus, for example, it’s:

• Lighter — no separate app needed after you have the ISO.
• Faster — one quick file swap instead of building a new USB from scratch.
• Portable — works with any ISO or USB you already have prepared.

Unless Microsoft changes the installer logic in future builds, this file-swap method will likely remain the quickest workaround for unsupported hardware such as your HP Z420 Workstation.

Anyway, in the off-chance you don't like W11, you have 10 days to roll back to Windows 10. After 10 days, unless you follow the steps outlined in this instructional video, you may need to do a fresh install of Windows 10. Either way, this video will show you what to do with easy-to-follow instructions: https://www.youtube.com/watch?v=2v9_-4JCh_U&ab_channel=Tips2Fix.

Kind Regards,

NonSequitur777