If it is the CC version and you are logged in with your Adobe account it is registered. It happens automatically. The Adobe Creative Cloud applet/program registers both LR and PS CC automatically as soon as you are signed in.
Could be you have a Slow Internet connection? Even with my fairly fast internet connection and fairly fast computer when I open the Adobe Creative Cloud applet it takes quit a few seconds to a minute for it to open completely. During that time it is connecting to the Adobe CC system.
