◆Railsインストール

gem install rails

ERROR:  Error installing rails:
        rake requires RubyGems version >= 1.3.2


D:\Ruby>gem install RubyGems-1.3.2
ERROR:  could not find gem RubyGems-1.3.2 locally or in a repository

http://rubyforge.org/frs/?group_id=126&release_id=46225
から1.32のrubygems をD:\Rubyへダウンロード

D:\Ruby>gem install rubygems -l
Successfully installed rubygems-update-1.3.2
1 gem installed

update_rubygems

RubyGems installed the following executables:
        D:/Ruby/bin/gem

再び
gem install rails

ERROR:  Error installing rails:
        rdoc requires Ruby version >= 1.8.7

下記から、Rubyの1.8.7をダウンロード
http://www.garbagecollect.jp/ruby/mswin32/ja/download/release.html

D:\Ruby>ruby -v
ruby 1.8.7 (2010-12-23 patchlevel 330) [i386-mswin32]

D:\Ruby>gem install rails
Depending on your version of ruby, you may need to install ruby rdoc/ri data:

<= 1.8.6 : unsupported
 = 1.8.7 : gem install rdoc-data; rdoc-data --install
 = 1.9.1 : gem install rdoc-data; rdoc-data --install
>= 1.9.2 : nothing to do! Yay!
ERROR:  Error installing rails:
        multi_json requires RubyGems version >= 1.3.6

gem update
D:\Ruby>gem install pkg-config --include-dependencies
INFO:  `gem install -y` is now default and will be removed
INFO:  use --ignore-dependencies to install only the gems you list
Successfully installed pkg-config-1.1.2
1 gem installed

D:\Ruby>gem install rails --include-dependencies
INFO:  `gem install -y` is now default and will be removed
INFO:  use --ignore-dependencies to install only the gems you list
ERROR:  Error installing rails:
        multi_json requires RubyGems version >= 1.3.6

D:\Ruby>gem update --system

D:\Ruby>gem install rails --include-dependencies
INFO:  `gem install -y` is now default and will be removed
INFO:  use --ignore-dependencies to install only the gems you list
ERROR:  Error installing rails:
        multi_json requires RubyGems version >= 1.3.6

gem install rails -v=2.1

D:\Ruby>gem install rails -v=2.1.0
Successfully installed activesupport-2.1.0
Successfully installed activerecord-2.1.0
Successfully installed actionpack-2.1.0
Successfully installed actionmailer-2.1.0
Successfully installed activeresource-2.1.0
Successfully installed rails-2.1.0
6 gems installed
Installing ri documentation for activesupport-2.1.0...