Launcher won't open

I've played league for about 2-3 years, and I've never had a problem other than my old computer being terrible. But just recently, when I try to launch league, the logo pops up for around 2 seconds as it usually does, but then it closes and doesn't open the launcher, I've tried to delete my lol_launcher, and even reinstalling lol, but nothing has worked. If someone can help me please do so, because I don't want to lose lol.