After launching project and opening a scene i got black screen.

as I said everything looks good until i choose a scene to open, then i get this

im not sure what to do tried reinstalling, also tried different version of unity. I am using 5.0.0f1 version now, OS windows 8.1 pro x64, and got nvidia geforce 840m graphic card. Also I got black screen even when I start unity with new project and then minimize/maximize program. Please any suggestion, solution would be appreciated.

Nope, seems like Unreal engine also had the same problem.

Perhaps changing the unity colors ?

Goto Unity->Preferences->Colors->Use Defaults.