Add enable long paths to Windows pip install guide.

PiperOrigin-RevId: 234158489

Author: lamberta

site/en/install/errors.md

@@ -305,4 +305,8 @@ ImportError: cannot import name 'descriptor'</pre>
   <td><a href="https://github.com/tensorflow/tensorflow/issues/22512">22512</a>, <a href="https://github.com/tensorflow/tensorflow/issues/22794">22794</a></td>
   <td><pre>ImportError: DLL load failed: The specified module could not be found.</pre></td>
 </tr>
+<tr>
+  <td><a href="https://github.com/tensorflow/tensorflow/issues/24835">24835</a></td>
+  <td><pre>Could not install packages due to an EnvironmentError: [Errno 2] No such file or directory: [long path name]</pre></td>
+</tr>
 </table>

site/en/install/pip.html

@@ -144,6 +144,7 @@ <h3>Windows</h3><!--python3-->
 <li>Select <em>Redistributables and Build Tools</em>,</li>
 <li>Download and install the <em>Microsoft Visual C++ 2015 Redistributable Update 3</em>.</li>
 </ol>
+<p>Make sure <a href="https://superuser.com/questions/1119883/windows-10-enable-ntfs-long-paths-policy-option-missing" class="external">long paths are enabled</a> on Windows.</p>
 <p>Install the <em>64-bit</em> <a href="https://www.python.org/downloads/windows/" class="external">Python 3 release for Windows</a> (select <code>pip</code> as an optional feature).</p>
 <pre class="devsite-terminal tfo-terminal-windows devsite-click-to-copy">pip3 install -U pip virtualenv</pre>
 </section>