If you know how that works, that might work. I tried once to mess with that, but its a frikkin study in its own right.
So you can just deactivate it for a sec, if that doesnt work, i would start googling. Google is your man when it comes to fixes for this kind of thing.
Launcher Closes Without Warning / Does not open when clicked
1. Try running as an admin by right clicking on the executable and selecting "Run As" and "Administrator"
2. Try removing and http://support.leagueoflegends.com/entries/234257-pvp-net-and-adobe-air.
3. Make sure your http://support.leagueoflegends.com/entries/234288-windows-settings-troubleshooting are set properly.
4. Make sure you're up to date on all of your Windows Updates (Service Packs)
5. If you recently did a system restore, had a virus or did a Windows reinstall, you may want to try http://support.leagueoflegends.com/entries/234176-reinstalling-league-of-legends.
From the first google search link.
Dont know how bad you want to play tomorrow, but if all these options dont work, im sure there are more. When looking at these 5, its from fastest solution to slowest if it judge that well.