Game Crash !

When game loads it stops working and at the bottom of screen theres written "Downloading..." Then animations stops to work, i can't do ALT+TAB and CTRL+ALT+DELETE because it isn't working... then after 10 minutes and error pops up telling that Client.exe stopped working... HELP PLEASE ! I downloaded game yesterday and played it long time... i don't hink so if it's my fault...