docs: function guessPython () {
      log.verbose('could not find "' + python + '". guessing location')
      var rootDir = process.env.SystemDrive || 'C:\\'
      if (rootDir[rootDir.length - 1] !== '\\') {
        rootDir += '\\'
      }
      var pythonPath = path.resolve(rootDir, 'Python27', 'python.exe')
      log.verbose('ensuring that file exists:', pythonPath)
      fs.stat(pythonPath, function (err, stat) {
        if (err) {
          if (err.code == 'ENOENT') {
            failNoPython()
          } else {
            callback(err)
          }
          return
        }
        python = pythonPath
        checkPythonVersion()
      })
    }