Remove mention of InstantRails, it is completely obsolete.

Mention RubyInstaller instead which is actually quite pleasant and runs Rails fine.

railties/guides/source/getting_started.textile

@@ -149,7 +149,7 @@ Usually run this as the root user:
 # gem install rails
 </shell>
 
-TIP. If you're working on Windows, you may find it easier to install "Instant Rails":http://instantrails.rubyforge.org/wiki/wiki.pl. Be aware, though, that Instant Rails releases tend to lag seriously behind the actual Rails version. Also, you will find that Rails development on Windows is overall less pleasant than on other operating systems. If at all possible, we suggest that you install a Linux virtual machine and use that for Rails development, instead of using Windows.
+TIP. If you're working on Windows, you should be aware that the vast majority of Rails development is done in Unix environments. While Ruby and Rails themselves install easily using for example "Ruby Installer":http://rubyinstaller.org/, the supporting ecosystem often assumes you are able to build C-based rubygems and work in a command window. If at all possible, we suggest that you install a Linux virtual machine and use that for Rails development, instead of using Windows.
 
 h4. Creating the Blog Application