Notebook Boot and Lockup

Hi,

when I start my notebook, I get the error messagt "The selected boot device failed. Press <Enter> to Continue". Yesterday it worked as usual. Then I saw some updates being installed by HP Support Assistent. Then there was a message, that a restart is required to complete the updates. I shut down the notebook one or two hours later. When I started it today, I got the error message.

I searched for the error message and tried the following:

- F2 - system diagnostics - system test: all tests passed successful

- reset the bios to factory defaults

- F11 - system recovery -  after pressing F11 only the error message appears

Then I created a bootable USB-Stick with a windows installation with the microsoft MediaCreationTool. So it should be possible to start from that USB-Stick in UEFI-Mode. With the default settings in the BIOS the notebook did not want to start from the USB-Stick (same error message - the selected boot device failed). So I changed the setting in the BIOS, that legacy support is enabled. Then the notebook started in legacy mode from the USB-Stick. I went to the command prompt and was able to access all hard disks and copy files, so the hard disks are working as they should. When I go to any of the repair options, I cant select anything. If I start a new installation of windows, I can choose no one of the hard disks, because they should be accessed in UEFI-Mode and I started the notebook in legacy mode.

Right now I dont have any more ideas. The automatic update (which required a restart) broke anything. And I dont know where the logs are located, so I cant tell which updates where installed.

Any ideas?

Greetings.