Windows 11 Hard Drive Not Installed Error
Solution 1:
Check to make sure the Microsoft offered you the Windows 11 update and that you did not make any system changes to force the computer to run Windows 11.
Then get the Dell Hardware test APP, make a bootable USB key from the Hardware APP and test all hardware, particularly the hard drive.
The bootable USB App bypasses operating system and checks all hardware.
It make be that the hard drive developed a hardware error at the last update (coincidence).
It seems reasonably clear the HDD has failed. You can also consider arbitrarily replacing it.