I forgot to jot down how many users I've already installed from my Office Home and Student 2010. How will I know if there is a remaining slot that can be installed? Or my only recourse is to install it? I know that Microsoft allows only 3 users to be installed. I have doubts that a friend of mine has installed this on his computer. Is there a way to know who used my Office 2010? Can Microsoft send users who installed a certain product? By IP address or what?