HELP! UnrealBuildTool was unable to generate project files

I am trying to build engine from the source, and no matter what I do, I always get the same error after executing GenerateProjectFiles.bat. It says that I don’t have VS installed. But I do have and it works with binary version of engine. I have VS 2015 professional update 3.
Does anyone know how can i fix this? I cant go on with my project. I am stuck for couple days because of this.
Thanks in advance.