After I installed the Unreal Engine, I would create a new project, I kept getting an error with this line at the end:
ERROR: No 32-bit compiler toolchain found in E:\Visual Studio 2015\VC\bin\cl.exe
It turned out that it was because I had an older version of Visual Studio installed (Version 2015). I assume it was looking at Visual Studio 2015 instead of Visual Studio 2017, and since I didn’t have C++ installed on the 2015 version, it kept prompting with this error.
I uninstalled the older Visual Studio 2015, and the Unreal Engine started right up!