title: Visual Studio 2010: impossible to add features
body: <p>On Windows 8.1, I installed Visual Studio 2010, then updated to SP1 + Windows Update fixes and installed Python Tools for Visual Studio 2.1.</p>
  
  <p>Now, I wanted to add a feature to my VS2010 installation. Unfortunately the setup fails with the message:</p>
  
  <pre><code>A selected drive is no longer valid.  Please review your installation path settings before continuing with setup.
  </code></pre>
  
  <p>In the installation log I find the following message:</p>
  
  <pre><code>[01/23/15,18:45:12] VS70pgui: ***ERRORLOG EVENT*** : Unable to retrieve the install directory for Microsoft Visual Studio Performance Collection Tools for v4.0 in COptionsPage::IsGoodAllComponenentsPath
  [01/23/15,18:45:12] vs70uimgr: Entering DisplayMessage() method.
  [01/23/15,18:45:12] vs70uimgr: DisplayMessage_START:A selected drive is no longer valid.  Please review your installation path settings before continuing with setup.
  [01/23/15,18:45:17] vs70uimgr: DisplayMessage_END:A selected drive is no longer valid.  Please review your installation path settings before continuing with setup.
  [01/23/15,18:45:17] VS70pgui: A selected drive is no longer valid.  Please review your installation path settings before continuing with setup.
  </code></pre>
  
  <p>I have not installed the <code>Microsoft Visual Studio Performance Collection Tools for v4.0</code> manually at all. <em>(However, during the installation I was informed that the kernel driver for CPU polling was incompatible with Windows 8.)</em></p>
  
  <p>I already tried uninstalling PTVS 2.1 but that did not help either. Any hints on how to get around this issue?</p>