Answer:
I'm found on Windows yet I am just a decoration. What am I?
I am a portal to another world which you cannot enter. Only you can see me but I can't see you.
You throw me away, I find my way back. Traditionally, I'm wooden with an arch in my back. What am I?
Iām tall when Iām young. Iām short when Iām old. I can light up your world. What am I?
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I've told you all, I cannot tell you more. What am I?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.