I have Windows 7 64b (Service Pack1) laptop and I use VisualStudio 2010. All previous Unity Editor builds work fine, BUT 5.6.0b6 Editor doesn't start - it gives error:
"The program can't start because MSVCP120.dll is missing from your computer. Try reinstalling the program to fix this problem."

How we can reproduce it using the example you attached
1 You need Windows 7 computer without VisualStudio 2013 (or later) installed
2 Install 5.6.0b6 build of Unity Editor
3 Try to open Unity.exe

Actual result:
Unity Editor is not started and the Windows-error appears:
"The program can't start because MSVCP120.dll is missing from your computer. Try reinstalling the program to fix this problem."

Expected result:
Unity Editor 5.6.0b6 should work without VisualStudio installation on Windows 7

------ workaround ------
Installing "Microsoft Visual Studio Community 2015" from Unity installer fixes this problem