I have Visual Studio on my machine, but EiffelStudio cannot find it

Here is a summary of steps to make sure C code compiles using Visual Studio 2017 in 64-bit mode on 64-bit Windows 10:

  1. Cleanup all projects by removing EIFGENs directories (including those in precompiles).
  2. Setup Visual Studio 2017 environment in 64-bit mode by running
      ...\vsdevcmd.bat -arch=amd64
  3. Setup EiffelStudio environment by running (most probably, this step is unnecessary if using GUI only)
  4. Tell EiffelStudio to use Visual Studio 2017-compatible libraries
      set ISE_C_COMPILER=msc_vc140
  5. Launch EiffelStudio from the command prompt:

See also: