Update download supernav to indicate that WinXP is not supported on W…

…indows for 3.5 or later

templates/downloads/supernav.html

@@ -11,14 +11,16 @@ <h4>Download for {{ data.os.name }}</h4>
             <a class="button" href="{{ data.python3.url }}">{{ data.python3.release.name }}</a>
             <a class="button" href="{{ data.python2.url }}">{{ data.python2.release.name }}</a>
         </p>
-        <p>Not the OS you are looking for? Python can be used on 21 different operating systems and environments. <a href="{% url 'download:download' %}">View the full list</a>.</p>
+        <p>{{navigator.appVersion}}</p>
+        {% if data.os.slug == 'windows' and data.python3.release.name >= 'Python 3.5' %}<p><strong>NB Python 3.5+ <em>cannot</em> be used on WinXP or earlier</strong></p>{% endif %}
+        <p>Not the OS you are looking for? Python can be used on many operating systems and environments. <a href="{% url 'download:download' %}">View the full list of downloads</a>.</p>
     </div>
     {% endfor %}
     <div class="download-unknown">
         <h4>Download Python for Any OS</h4>
-        <p>Python can be used on 21 different operating systems and environments.</p>
+        <p>Python can be used on many operating systems and environments.</p>
         <p>
-            <a class="button" href="{% url 'download:download_full_os_list' %}">View the Full List</a>
+            <a class="button" href="{% url 'download:download_full_os_list' %}">View the full list of downloads</a>
         </p>
     </div>
 </li>