When I am trying to install CMake I get the error:
Visual Studio 15 2017 could not find any instance of Visual Studio.
I am using Windows 7
I ran into the same error and performed the following steps to resolve the issue:
These steps resulted in the "Visual C++ tools for CMake" feature being installed, but the other optional C++ features included in this workload may also helpful for what you are trying to do.
After the Visual Studio updater finishes installing try re-running the command. You may need to open a new command window.