We always encourage not to have a CLASSPATH set.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@557907 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/install.html

@@ -221,9 +221,10 @@ restrictions on the classes which may be loaded by an extension.</p>
   <td width="5%">&nbsp;</td>
   <td>
     The ant.bat script makes use of three environment variables -
-    ANT_HOME, CLASSPATH and JAVA_HOME. <b>Ensure</b> that if
-    these variables are set, they do <b><u>not</u></b> have quotes (either
-    ' or &quot;) and they do <b><u>not</u></b> end with \ or with /.
+    ANT_HOME, CLASSPATH and JAVA_HOME. <b>Ensure</b> that ANT_HOME and JAVA_HOME variables are set, 
+    and that they do <b><u>not</u></b> have quotes (either
+    ' or &quot;) and they do <b><u>not</u></b> end with \ or with /. CLASSPATH should be unset or 
+    empty.
   </td>
 </tr>
 </table>