def interpreter
      # force 64-bit powershell from 32-bit ruby process
      if ::File.exist?("#{ENV['WINDIR']}\\sysnative\\WindowsPowershell\\v1.0\\powershell.exe")
        "#{ENV['WINDIR']}\\sysnative\\WindowsPowershell\\v1.0\\powershell.exe"
      elsif ::File.exist?("#{ENV['WINDIR']}\\system32\\WindowsPowershell\\v1.0\\powershell.exe")