Davinci Resolve 15 won't start after BIOS reset

So yesterday my pc crashed. It would switch on but there would be no image. To solve this I did a BIOS reset by removing the battery of the mainboard. It helped, but ever since I can't open resolve anymore. I reinstalled it and tright opening it as a administrator, but nothing seems to work. Any ideas? I've read people deleting everything related to davinci, but how do I backup my projects?

figured it out. Download "DDU", start in safe mode and uninstall de onboard graphic drivers.