The pc is an acer aspire z5610, please find more details here:
https://www.cnet.com/products/acer-aspire-z5600-all-in-one-core-2-duo-e7500-2-93-ghz-4-gb-1-tb-lcd-23/
In the meanwhile the back-up got cloned and the bluescreen disappeared, I checked the BIOS for enabling multiple cores, but...