title: Updating Ruby 1.9.3 -> 2.0.0 without losing gems
body: <p>Have had 1.9.3p194 (RubyInstaller) with Ruby on Rails and all kinds of Gems installed on my WinXP. Now I want to update the whole setup.</p>
  
  <p>Updating RoR (to 4.0.0) and gems was easy: <code>gem update rails</code>, <code>gem update --system</code>, <code>gem update</code>.</p>
  
  <p>But how do I do that with Ruby? Is there an easy way to update the installation?</p>
  
  <p>If not, and I have to install the fresh package, then how do I do it with little hassle?</p>
  
  <p>I have downloaded the fresh 2.0 RubyInstaller. I have read that I shouldn't install this new Ruby version in the same directory as my old Ruby version (<code>c:\programs\Ruby</code>) that's why I chose a <code>c:\programs\Ruby200</code> directory. During the installation I clicked on every additional setting, including the "include new directory in the PATH variable" type of choice. But now when I type <code>ruby -v</code> I still get 1.9.3p194 and the new directory is absent from PATH (I haven't rebooted, so maybe this has something to do with it).</p>
  
  <p>So how should I really install the new version? Should I simply change the old PATH to the new one? Or should I instead only add the new one without removing the old path (so there will be some kind of advantage of having both 1.9.3 and 2.0)? Or should I simply delete both installations and install 2.0 from the start?</p>
  
  <p>How do I easily transfer the gems (or the list of them, so the <code>gem update</code> could handle the installation/updating) from my old installation to the new one?</p>
  
  <p>I am using JetBrains RubyMine 5.4 editor, and would like to know if I need to do something there as well (for both the new and the existing projects).</p>