Redmine

Fetching gem metadata from http://rubygems.org/.........
Fetching gem metadata from http://rubygems.org/..
Using rake (10.0.3)
Using i18n (0.6.1)
Using multi_json (1.5.0)
Using activesupport (3.2.11)
Using builder (3.0.0)
Using activemodel (3.2.11)
Using erubis (2.7.0)
Using journey (1.0.4)
Using rack (1.4.4)
Using rack-cache (1.2)
Using rack-test (0.6.2)
Using hike (1.2.1)
Using tilt (1.3.3)
Using sprockets (2.2.2)
Using actionpack (3.2.11)
Using mime-types (1.19)
Using polyglot (0.3.3)
Using treetop (1.4.12)
Using mail (2.4.4)
Using actionmailer (3.2.11)
Using arel (3.0.2)
Using tzinfo (0.3.35)
Using activerecord (3.2.11)
Using activeresource (3.2.11)
Using bundler (1.2.3)
Using coderay (1.0.8)
Using rack-ssl (1.3.2)
Installing json (1.7.6) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension
.

D:/Adhi30/Ruby193/bin/ruby.exe extconf.rb
creating Makefile

make
generating generator-i386-mingw32.def
compiling generator.c
make: gcc: Command not found
make: *** [generator.o] Error 127

Gem files will remain installed in D:/Adhi30/Ruby193/lib/ruby/gems/1.9.1/gems/js
on-1.7.6 for inspection.
Results logged to D:/Adhi30/Ruby193/lib/ruby/gems/1.9.1/gems/json-1.7.6/ext/json
/ext/generator/gem_make.out
An error occurred while installing json (1.7.6), and Bundler cannot continue.
Make sure that `gem install json -v '1.7.6'` succeeds before bundling.

help me

thanks in advance