Hi forum!

I'm posting this, because i know how frustrating those errors are. It took me about 3-4 weeks before i got my game running again, the problem started after the server split.
So here are the list of things that i did:

1) Disabled firewalls, one under the control panel and the second under the antivirus program preferences or (options) I have Bitdefender 2011.
2) I had deleted the temp file in the Riot Games main directory.
3) Running the game as admin.
4) After the server split, uninstalled the game (about 10 times :S ), and downloaded again under my region.

Though every time i enter the game i must disable both firewalls and not the Hamachi adapter (if you have Hamachi).

I hope this helped in any way, tried my best!
Btw, i'm on 64-bit Windows 7.

i have fixed it the other way 100 percent works !!!!!!!!!
First right click on Play Leauge of Legends then you go to trubleshoot compability
Then go to Try Recomended Settings and then click start program wait a litle bit 15 sec.And it will start!!!!!!!!!!
But you must start it every time like that.