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")