Gem install ruby-serialport gives error


:::: gem install ruby-serialport
Install required dependency echoe? [Yn] Y
Install required dependency rubyforge? [Yn] Y
Install required dependency highline? [Yn] Y
Building native extensions. This could take a while…
ERROR: While executing gem … (Gem::Installer::ExtensionBuildError)
ERROR: Failed to build gem native extension.

ruby extconf.rb install ruby-serialport -p
checking for OS… mswin
creating Makefile

‘nmake’ is not recognized as an internal or external command,
operable program or batch file.

Gem files will remain installed in
t-0.7.0 for inspection.
Results logged to

i m facing this problem can anyone help me ??