Boot Options

[Jackobli]

Any idea, when and where they will advise me?

[mbirger]

I've sent a reminder, but does your SD card appear in BIOS menu? Is it detected?

[Jackobli]

Great, played with boot options (Dual, Legacy, UEFI) and then found, that one must scroll all down the the end of the screen to find the hard disk options/priorities.
Have to try tomorrow, if this works as intended and the removal of the SD card leads to boot from internal SSD.