Editor freezes whenever clicking on dropdown menus

I’m posting in rendering section because I think that is a problem related to my pc not able to render correctly UE user interface.

THE PROBLEM:
Clicking on almost any menu that should open a dropdown list makes instantly the editor not responding, hence I’m forced to kill all its processes. Why almost? Because some opens but flickering.

E.g.: right click in the viewport, everything opens a flickering dropdown list except from “attach to” which freezes the editor.
After the editor freezes, the graphics of the menu I tried to open stays static (is always visible on my display also if I open other programs).

A photo:

SOLUTIONS TRIED:

  • reinstalling graphic cards drivers (nothing changed)
  • reinstalling unreal engine (nothing changed)
  • using “-opengl” as target (fixed issue opening the launcher)
  • modifying “windowswindow.cpp” (nothing changed)
  • disabling “windows composition” (made editor and launcher not responding and not possible to open them)

If anyone can help me please I’d be very thankful.

MY SETUP:

OS: Win7 64-bit SP1

CPU: i7-4710MQ CPU @ 2.50GHz (8 CPUs)

RAM: 8gb

GPU: Nvidia GeForce GTX 860M

I also attach the [DxDiag][2] for further details.