guide linking to wrong pages fix
diff --git a/user_guide/overview/at_a_glance.html b/user_guide/overview/at_a_glance.html
index a4d0f36..6dc9287 100644
--- a/user_guide/overview/at_a_glance.html
+++ b/user_guide/overview/at_a_glance.html
@@ -159,7 +159,7 @@
 

 <div id="footer">

 <p>

-Previous Topic:&nbsp;&nbsp;<a href="../installation/upgrading.html">Upgrading from an Older Version</a>

+Previous Topic:&nbsp;&nbsp;<a href="../installation/troubleshooting.html">Trouble Shooting</a>

 &nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

 <a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;

 <a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;