下载rails，本文下载的是rails2.0.2版本（下载后的文件名是：rails-2.0.2.zip），下载地址为：http://rubyforge.org/frs/download.php/29361/rails-2.0.2.zip

gem命令行：

gem install D:\ruby\rails\rails\vendor\rails\activesupport\pkg\activesupport-2.0.2.gem
gem install D:\ruby\rails\rails\vendor\rails\activerecord\pkg\activerecord-2.0.2.gem
gem install D:\ruby\rails\rails\vendor\rails\actionpack\pkg\actionpack-2.0.2.gem
gem install D:\ruby\rails\rails\vendor\rails\actionmailer\pkg\actionmailer-2.0.2.gem
gem install D:\ruby\rails\rails\vendor\rails\activeresource\pkg\activeresource-2.0.2.gem

gem install D:\ruby\rails\rails\vendor\rails\railties\pkg\rails-2.0.2.gem

另：官网：

http://rubyonrails.org/download