Then, click on Recovery HD and click on the Upward arrow under it. See screen clip below.Make sure you first select the WiFi network below. Instead, it will show two hard disks One is your actual hard drive which stores all the data. This will turn on your mac but it will not directly boot to the desktop.
I have followed these steps on my MAC OSX 10.9 Mavericks and everything works fine after that. This post will explain all the steps that need to be taken in order to do a factory reset to your MAC.
