How do I get my layers tab to show up again?

A few days ago while working on photoshop, my younger sibling messed around and made the layers tab disappear. From what she tells me, she accidentally drug it out of the pse7 window and it hasn't shown up since. I've tried logging off and logging back onto my computer, shutting it down and restarting, but of course none of that has worked. Any help, please?