BugsPlat after launching Alpha client

So, I got a really serious problem here. Days ago I formatted and installed (again) windows 7. Everything was fine since I installed League Of Legends.

First of all I got : "Unespicified error occurred..." in the legacy client, then I reinstalled and used the alpha client. The error was diferent: "Error 004...". After deleting many files and reinstalling the game many times (1 week doing this) , I used the Hextech Repair Tool to do a clean uninstall and it worked. Well, until now. Got bugsplat while patching (alpha client [admin]). When I launch the alpha client I get instant bugsplat.

HELP! My vacations are ending and I don't have much time during work time... I'm trying to solve this for a week!