The screenshot you included is of Open Firmware (Command-Option-O-F), not single-user mode (Command-S). Those commands will not work there. Try Command-S again, and you should get a single-user mode Terminal window like in the video.
-Which model PowerBook G4?
-Which version of Mac OS 9/OS X are you going to install/use?
-Do you have the original install discs that came with the PowerBook?
OK, that is a PowerBook G4 (12-inch 1.5GHz). The folder icon means it cannot find a bootable OS.
Again, Open Firmware will not help you to restore the Mac to factory defaults as far as Mac OS X is concerned. You will need the Mac OS X install discs to install an operating system. You will need the exact version of gray install discs that came with a 12" PowerBook G4, or a retail disc with Mac OS X 10.3.7 through 10.5.8.
-Can you perform an Option boot? Does it give you a choice of drives to startup from, i.e. Startup Manager?
-Do you have any Mac OS X install discs of the above versions at all?
OK...maybe one of the keys is bad, preventing you from Option booting or Command-S booting.
When you are in Open Firmware, try the following commands in the order below:
reset-nvram then Enter/Return
set-defaults then Enter/Return
reset-all then Enter/Return (the Mac should restart - then try Command-S or Option booting)
I have been thinking about this, and I have actually overlooked an obvious thing and misguided you a bit. It seems that the hard drive either doesn't have an OS on it, or it is heavily corrupted, so that is why you cannot boot into single user mode (Command-S).
You are going to have to find some install discs to get OS X installed. If you have a Mac OS X install disc inserted, you will be able to Option boot or hold the C key down to boot from the disc. That will then allow you to install OS X.
When you try to enter singe user mode, are you pressing Command-S immediately after power on and before hearing the chime, then holding them until you see the black loading screen?
The videos you will see on YouTube about restoring a Mac to factory specs using single user mode without the install discs assume that you have a working version of Mac OS X installed on a working hard drive.
I have a Mac OS X CD, but if i want to Install them, get error.
When i press the power button and release and press cmd+s and then release, get question mark.
When i press the powerbutton and then release and immediately press cmd+s i get the question mark.
When i press cmd+s and the power button together to the end i get to firmware and the CD go out.