How long does it take to reset a Galaxy s3?

[Rulersky2]

Its currently taking me more than a hour. What is a explanation for this?
Please!!! I just want to get this stupid thing to work

 

[mydian]

Welcome to the forum! It should only take 5 minutes or so. Not long at all. You might have to reflash the stock rom with Odin.

Edit: What carrier? Custom or stock rom? If stock was the phone rooted? I'm just trying to get an idea why it happened and where to go from here.