title: Can't run c++ build task in VSCode
body: <p>I have this code in VSCode:</p>
  
  <pre><code>{
      "version": "2.0.0",
      "tasks": [
          {
              "taskName": "build first program",
              "type": "shell",
              "command": "g++",
              "args": [
                  "-g", "firstprogram.cpp"
              ],
              "group": {
                  "kind": "build",
                  "isDefault": true
              }
          }
      ]
  }
  </code></pre>
  
  <p>which is pretty much the exact same code in the official guide to debugging, but it says that <code>g++ is not recognized as a cmdlet, function, script file, or operable program</code>. Pretty much all of the rest of my code is copied from the official thing, aside from code specific to my program, and I have the MinGW c++ compiler. </p>