My os: windows xp, ruby: 1.8.7, rails: 2.3.5

Everything was fine, but I just installed a "gcc-4.4.0-mingw32-bin", and run gem install rdiscount, then my rails can't start.

Now when I run ruby script/server, or rake gems:install, the following error will occur:

rake aborted!
Malformed version number string mingw32

(See full trace by running task with --trace)

E:\WORKSPACE_TOPCODER\wenda_ror>ruby script/server
=> Booting Mongrel
=> Rails 2.3.5 application starting on http://0.0.0.0:3000
E:/Ruby/ruby-187/lib/ruby/site_ruby/1.8/rubygems/version.rb:182:in `initialize': Malformed version number string mingw32 (ArgumentError)
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:105:in `new'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:105:in `version_for_dir'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:47:in `refresh!'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:45:in `each'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:45:in `refresh!'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/vendor_gem_source_index.rb:29:in `initialize'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:21:in `new'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:21:in `add_frozen_gem_path'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:298:in `add_gem_load_paths'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:132:in `process'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `send'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/initializer.rb:113:in `run'
        from E:/WORKSPACE_TOPCODER/wenda_ror/config/environment.rb:9
        from E:/Ruby/ruby-187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from E:/Ruby/ruby-187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from E:/Ruby/ruby-187/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:156:in `require'

Now I have re-installed my ruby and rails, but the same error still occurs. And I have searched in google, found no solution. It seems I have to re-install my windows xp. Somebody knows the reason? Help...