Crashes Portal 2 and Steam hangs. (Portal 2)

I encountered a problem Portal 2 it crashes, I know that there are a lot of discussions on the forums, but I have Portal 2 different crashes. Start the game, screen saver Valve passes, loaded the game, all good, but start wild lags!, then again, the picture is smooth, then for 5 minutes, even worse lag and the game freezes and I get on the desktop of the computer. And Steam becomes blurred and it is clear that he is stuck and even after half an hour of Steam does not droop, it is necessary to close it, but after launch, Steam is running as if nothing had happened. It Beemod'and (a program to improve the editor Test. cameras). Many times I have re-installed Portal 2, tried to run without Beemod'a, was launched .EXE file run Portal 2 as Administrator, but nothing(. There is a solution? I have Windows 10 x64, CPU: Intel Core i7, graphics card: Geforce 750 is not the best, but with it I have Portal 2 worked without lags.