UE4-crashing

hi, I downloaded UE4-4.19.2 but it keeps crashes all the time in random situations with no specific action,
can someone help me?
I have a Lenovo Z51-70
corei7 5500u, 4GB RAM, AMD Radeon R9 M375.
here is my crash log link text

By the looks of it, your computer does not have:
aqProf.dll
VtuneApi.dll
VtuneApi32e.dll

Also, Unreal Engine recommends 8GB of Ram so a lack of Memory could also be the problem

and at the very end, it looks like the connection was cut, I’d try checking your firewall to make sure Epic Games and Unreal and allowed connections to and from your computer.

if you need anything else please let me know

I checked the firewall there was no block on them and my friend can use it and he has a 4GB RAM and I search for the dll but with no use, can’t find them anywhere and I’m gonna get crazy. I tried more than one version but it all report the same error.