Critical error in multiplayer

In multiplayer, a critical error pop up a 2-3 round.
Windows 7 Home Basic sp1 32 bit
Video card: ATI radeon msi HD5770 1Gb
Motherboard: sAM3 Gigabate GA-MA790XT-UD4P, RTL
Processor: AMD Phenom II 965 Black Edition 3,4 Hz
Sound Card: Realtek Hight Definition Audio
Driver is updated and the video card and sound card. Reinstalling windose and games has not helped. Derekt X last.
Help someone solve this problem!!