Exe the game from STEAM (if you have non-steam version, add shortcut etc..) Make sure you can access STEAM overlay. Press W and when you want to leave it running, press the key to open STEAM overlay (preferably if it's just 1 key, some key boards won't accept so many buttons pressed at once) Magically your character will be still running. To cancel run, hit W again. You can do this with any action.