Swapped HD, now Windows 7 won't boot up

[jayinc11]

Thinkpad X2, 16gb Ram, 500GB drive

Recently I switched above HD with a 1tb ssd and installed windows 11 pro (Optimum flavor).
I still want to boot up Win7. So I switched the HD again and this time Win7 did not boot up. It stops on the black screen with a cursor blinking, top left. What's the fix here?

 

[samuria]

It will be bios settings 11 sets it to secure boot, tpm, uefi so they wont match 7

 

[flavallee]

If I understand you correctly:
Your Lenovo ThinkPad X2 was running Windows 7 in a 500 GB HDD?
You removed the HDD with Windows 7 and installed a 1 TB SSD?
You installed Windows 11 in the SSD?
You removed the SSD with Windows 11 and reinstalled the HDD with Windows 7?
Your laptop will no longer boot?

What is the exact serial number on your Lenovo ThinkPad X2?
What Windows operating system did it originally come with?