Hello AaLF,
If you don't want password protection when resuming from screen saver, then the tutorial below can show you how to disable that.
Screen Saver Password Protection -Enable or Disable
If you don't want to use hibernate at all, then disabling it would be the easiest way.
Hibernate - Enable or Disable
If the screen saver is not working at all, then you might see if running a
SFC /SCANNOW command may help if you have a corrupted system file at fault.
Hope this helps,

Shawn