I was using BackTrack 5 R3 then Kali came out. So i downloaded it from the official site with deafualt settings and installed it with windows 7 same way that is described in official site. I am using HP Pavilion G4 laptop. Whenever i start Kali from Grub menu it start loading and suddenly all screen disappear or all screen goes black waited 10 to 15 min for display to come back but it did not come back. i restarted alot of time kali but all in vain everytime the same problem . Whats this problem anbody konws the solution. i failed to find any solution on google and on this forum so far. help me