'csc' is not recognized as an internal or external command, operable program or batch file

Question

I'm fairly new to C# and I'm trying to use cmd to compile a basic hello world file called test.cs. It contains the following:

// Similar to #include<foo.h> in C++, includes system namespaces in a program

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    // A name space declaration, a class is a group of namespaces
    namespace Program1
    {
        class Hello // my class here, classes can contain multiple functions called methods which define it's behavior
        {
            static void Main(string[] args) // main method, just like in C/C++ it's the starting point for execution cycle
            {
                Console.WriteLine("Hello World");
                Console.ReadKey(); // similar to _getch() in C++ waits for user to input something before closing
            }
        }
    }

    /*
     * Other notes, .cs is a c# file extension
     * cs files can be built via terminal by using csc foo.cs to generate foo.exe run it with foo
     */

When I try to run the line csc test.cs I get the following output:

Answer 1

Locate the path of csc.exe and add it your PATH environment variable.

In my case, the path for 64-bit C# compiler is C:\Windows\Microsoft.NET\Framework64\v4.0.30319.

Similarly, you can look for 32-bit C# compiler in C:\Windows\Microsoft.NET\Framework under different .NET framework version directories

There will be csc.exe for all versions like v2.0.XXXXX and v3.5. Select the one with the highest version in Framework64/Framework directory depending on your requirement.

Copy the path of csc.exe and add it to the PATH system environment variable.

Quit the cmd, and then launch again and run the program. That'd work.