Dell Inspiron N5110 Factory Reset Help

I'm trying to do a factory reset on my Dell laptop. I didn't receive a CD when I bought it so I tried doing it through the BIOS. I hit F8 repeatedly and got to the repair your computer screen. I selected that option and then it shows a screen that says Windows loading files. Unfortunately, after that it just freezes once the loading bar is full. Then after maybe 10 minutes it goes to resuming Windows normally (I assume a time out of some sort). 

Is there another way to do a factory reset? Like I said I don't have the CD because it didn't come with it. Or maybe I'm doing something wrong? Thanks