Occasionally I've had seen issues with Windows Updates
Sometimes when updates run they will update a driver or a .dll we don't want updated. Due to some misalignment with an update or bugfix some of the issues you are experiencing will arise.
Typically I will show hidden hardware using this procedure.
Afterword, I will delete all video related devices and allow the generic driver to operate the display. Then, run windows update and ensure you have all of your service packs/drivers up to date from Microsoft.
After that is complete, get the factory driver and install it for your GPU. This will hopefully give you a nice clean and uncontaminated driver install.