i just got on my pc wating to play rainbow six so i go on steam to open it its on gray text i was like "wtf?" and then i see install LIKE THERE WAS JUST THE BREAKING POINT THE **** HAPPENED I WAS DOWNLOADING BATTLESHIP AND NOBODY ELSE TOUCHED MY PC {so there goes the askers of did someone touch it} AND NOW I GOTTA DOWNLOAD 27 MORE GIGS SO I CAN PLAY THE GAME AGAIN
Very strange, Have you restarted your client / system to confirm the game still does not show up as installed? If you didn't remove the game I can't think of any reason this would occur.
Our support team can also help you with troubleshooting if you're interested : Support.ubi.com