Powerpoint changed display setting of HDMI need help

I was in powerpoint 2013 on my acer laptop which is plugged into a samsung flatscreen and i went into slideshow mode and when i came out of it and exited powerpoint all i could see on my tv was my pc's background. the sound is working but in order for me to get what im looking at on my pc on the tv i have to drag it way over to the right. i think powerpoint extended the display but idk how to revert it. I tried unplugging and restarting but no good