why is hp intel core i5-7400 cpu not compatible with windows 11?

[cajust]

why is hp intel core i5-7400 cpu not compatible with windows 11?

[Paul_Tikkanen]

Because Microsoft drew the W11 supported processor cutoff at the Intel 8th gen core processors, leaving those of us that have perfectly fine PC's with the 7th gen core processors out in the cold.

I didn't let that stop me from upgrading my PC's to W11...

If you want to install W11 on your PC as is, you can bypass the W11 hardware requirements using two easy methods.  The first one is the easiest.

I would make a system image of your current W10 installation prior to updating to W11, so you can easily reinstall W10 in the future.  I used the free Macrium Reflect software to do that, under the Backup at Home section. 

Along with the system image, make sure you create the bootable DVD or USB rescue drive you boot from to access the system image stored on your portable hard drive.

Macrium Software | Reflect Free Edition

Read and follow the instructions at the link below.

Windows 11 Upgrade Hack on Any Hardware | Dong Knows Tech

No registry changes needed.  No need to create installation media.  Just download the W11 ISO file, and the guy's zip file.

I used the first procedure to do an in-place upgrade an old HP Elitebook 6930p notebook made in 2010 to W11, and I was able to keep my old Office 2010 Starter program that came with the notebook when it had W7 on it, along with all of my other programs, files and settings.

The notebook met none of the enhanced W11 hardware requirements.

That is the 11th unsupported W11 PC I have upgraded to W11, and not one of them have had any issues whatsoever.

They have all gotten all the Windows 11 updates released thus far.

I check those against a PC I have that is fully supported to run W11.

There is also this way you can upgrade to W11, bypassing the hardware checks...

https://www.youtube.com/watch?v=02mgrA51974