The problem is the switchable graphics. If it had one or the other then likely the reference driver would work, but fall down because it doesn't know what to do with both in a switchable configuration.
As far as fixing it if System Restore didn't work and you don't have a known good backup system image from before this started, unfortunately the only way I know of to fix it is to re-install Windows.
so the moral of the story is let HP figure out which is best
Sadly that is the case with most laptops regardless of who made it, and equally so with any that do have switchable graphics (any combination of AMD/AMD, AMD/Intel, Nvidia/Intel).