league why

I like playing league, but recently, I had to restore my laptop to factory settings due to a virus. I reinstall league, and go into a game. When the game started, I tried to go to top lane, but for some reason, my character starts moving straight down mid the the enemy fountain, and I cant move any other way. My movement spells also make me go along my doom path. Then, all of a sudden, my game just exits out without seeing the screen that prompts me to reconnect. Eventually, this issue got fixed, and I decided to go to a ranked game. At the middle of the game, league decides to crash, again, without showing me the reconnecting screen. I try to open league back up, but to no avail. I return on someone elses PC and at the end, I get a leaver buster. I haven't played league becuz im afraid of crashing once more. Riot plz fix this