Avast protect ?

does avast protect from crash cpu ?

What exactly do you mean?

i mean if avast protect you of the crash(bug,lag)

A CPU crash is often caused by hardware, rather than software failure. Overheating being the most likely and common problem. Avast can not prevent that.
A little more information about the type of crash you are having might help.

ok i agree with you i just wanted to ask i didnt got any crash for the moment im really happy to got avast to secure my cpu ;D