Index: DamClients/DamUI/trunk/Dam.Setup/Product.wxs
===================================================================
diff -u -r6643 -r6646
--- DamClients/DamUI/trunk/Dam.Setup/Product.wxs	(.../Product.wxs)	(revision 6643)
+++ DamClients/DamUI/trunk/Dam.Setup/Product.wxs	(.../Product.wxs)	(revision 6646)
@@ -5,9 +5,23 @@
   <?define ProductExtension=".damx"?>
   <?define ProductDescription="Analysis and management of flood defence systems"?>
   <?define ProductManualTitle="DAM UI - User manual"?>
+  
   <Package Name="Deltares $(var.ProductName)" Language="1033" Version="$(var.ProductVersion)" 
            Manufacturer="Deltares" UpgradeCode="ACFF668C-B877-4A28-8422-65D04B09394D" InstallerVersion="200">
-    
+
+    <!--Look for proper version of Ds_Flex (>= 7.8.0.0) -->
+    <Property Id="DSFLEXVERSION" Secure="yes">
+      <RegistrySearch Id="DSFlexVersion"
+                      Root="HKLM"
+                      Key="SOFTWARE\WOW6432Node\WL | Delft Hydraulics\DS_Flex"
+                      Name="InstallerVersion"
+                      Type="raw" />
+    </Property>
+
+    <!-- Add the launch condition for the check on Ds_Flex -->
+    <Launch Message="There is a problem. The Ds_Flex Files are missing or too old. A new version must be installed before we can install [ProductName]."
+            Condition="Installed OR (DSFLEXVERSION >= &quot;7.8.0.0&quot;)" />
+
     <!-- Specify the required product components -->
     <!-- Program and manual -->
     <ComponentGroup Id="ProductComponent" Directory="INSTALLFOLDER">
@@ -18,7 +32,7 @@
     <CustomAction Id="SetTutorialsDir" Property="PROGRAMTUTORIALS" 
                   Value="C:\Users\Public\Documents\Deltares\$(var.ProductId)"/>
     <InstallUISequence>
-      <Custom Action="SetTutorialsDir" Before="CostInitialize" Condition="NOT Installed"></Custom>
+      <Custom Action="SetTutorialsDir" Before="CostInitialize" Condition="NOT Installed"/>
     </InstallUISequence>
 
     <ComponentGroup Id="TutorialFilesComponent" Directory="PROGRAMTUTORIALS">