Now, you might be wondering that how to install apps that I have already bought. Its is also possible and we are going to that next.
Here are the instructions. • Now, right click anywhere in
Store or
swipe down from top to bring the app bar from top. Here press ‘
Your apps’.

• ‘Your apps’ page will open and show all the apps you have bought/installed using this Microsoft account on any device. Here select the ones you want to install on this PC and press ‘Install’ from the bottom app bar.

• Your apps will start installing.
source:windows8core