but if i want e.g. click on "file->new project" or "options->audio" or anything, it resets.
I agree with the consensus here; probably a flaky driver, but stranger things have happened to me. The 'new project' failure might lead me to believe that a corrupted template file was a possible cause. When all else fails, you can try renaming the Template.p5t file in the Project5 Version 2 folder. Then when you re-launch, P5 will use settings that are generated from its own "hidden" template 'file', and any success with this procedure would indicate a corrupt template.
If that's the case, then close down the app, delete the renamed template.p5t, and resave a new one after re-launching. If no template.p5t is listed, that means that you've never used the Save as Template command, and you'll have to look elsewhere for the root cause of the BSOD. Just another option; I still speculate a driver issue.