title: Rails 4, rails server error
body: <p>When I run <code>rails server</code>, I have the following error:</p>
  
  <pre><code>rails server                                                                                                       
  =&gt; Booting WEBrick                                                                                                 
  =&gt; Rails 4.0.2 application starting in development on localhost:3000                                          
  =&gt; Run `rails server -h` for more startup options                                                                  
  =&gt; Ctrl-C to shutdown server                                                                                       
  [2013-12-26 23:29:07] INFO  WEBrick 1.3.1                                                                          
  [2013-12-26 23:29:07] INFO  ruby 2.0.0 (2013-11-22) [i386-mingw32]                                                 
  [2013-12-26 23:29:07] WARN  TCPServer Error: Only one usage of each socket address (protocol/network address/po    
  rt) is normally permitted. - bind(2)                                                                               
  Exiting                                                                                                            
  C:/Ruby200/lib/ruby/2.0.0/webrick/utils.rb:85:in `initialize': Only one usage of each socket address (protocol/    
  network address/port) is normally permitted. - bind(2) (Errno::EADDRINUSE)                                         
          from C:/Ruby200/lib/ruby/2.0.0/webrick/utils.rb:85:in `new'                                                
          from C:/Ruby200/lib/ruby/2.0.0/webrick/utils.rb:85:in `block in create_listeners'                          
          from C:/Ruby200/lib/ruby/2.0.0/webrick/utils.rb:82:in `each'                                               
          from C:/Ruby200/lib/ruby/2.0.0/webrick/utils.rb:82:in `create_listeners'                                   
          from C:/Ruby200/lib/ruby/2.0.0/webrick/server.rb:132:in `listen'                                           
          from C:/Ruby200/lib/ruby/2.0.0/webrick/server.rb:113:in `initialize'                                       
          from C:/Ruby200/lib/ruby/2.0.0/webrick/httpserver.rb:45:in `initialize'                                    
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/handler/webrick.rb:11:in `new'                
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/handler/webrick.rb:11:in `run'                
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/rack-1.5.2/lib/rack/server.rb:264:in `start'                      
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/railties-4.0.2/lib/rails/commands/server.rb:84:in `start'         
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:76:in `block in &lt;top (req    
  uired)&gt;'                                                                                                           
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap'                  
          from C:/Ruby200/lib/ruby/gems/2.0.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `&lt;top (required)&gt;'     
          from bin/rails:4:in `require'                                                                              
          from bin/rails:4:in `&lt;main&gt;'   
  </code></pre>