Code Builder does not work

I installed the following two things:

• intel_sdk_for_opencl_setup_6.0.0.1049.exe
• opencl_runtime_16.1_x64_setup.msi

Now when I click on any of the Code-Builder menu items in Visual Studio I get the following error:

Code Builder initialization failed:

Unable to load DLL 'KernelBuilderAPI.dll': The specified procedure could not be found. (Exception from HRESULT: 0x8007007F)

I verified that KernelBuilderAPI.dll exists in both C:\Program Files (x86)\Intel\OpenCL SDK\bin\[x86/x64] - but neither of these paths has been added to my PATH environment variable (is this normal?):

Here are some further infos about my system:

• Visual Studio Enterprise 2015 Version 14.0.25123.00 Update 2
• Windows 7 Enterprise Service Pack 1, 64Bit
• Intel Xeon CPU E3-1271 v3 @ 3.60GHz
• NVIDIA Quadro K4000