Hardcodes the Product Id of the Windows MSI in order to have its different builds recognized as one and the same product.

resources/install/ant-build-config.properties

@@ -5,4 +5,5 @@ package.name=sip-communicator
 installer.welcome.wtext1=This software is developed by: SIP Communicator <sc@sip-communicator.org>
 installer.welcome.wtext2=The homepage is at: http://sip-communicator.org/
 installer.welcome.wtext3=
+wix.product.id=ACD610AA-E7F1-4644-894D-D8A31894A241
 wix.upgrade.code=B3854E66-BAE5-409F-B5EB-7649CB48F99A

resources/install/build.xml

@@ -433,6 +433,7 @@
         <filter token="APP_NAME" value="${application.name}" />
         <filter token="APP_WEB" value="${application.web}" />
     	<filter token="WINDOWS_JRE_FILE" value="${windows.jre.file}" />
+        <filter token="WIX_PRODUCT_ID" value="${wix.product.id}" />
         <filter token="WIX_UPGRADE_CODE" value="${wix.upgrade.code}" />
         <copy
                 file="${inst.resrc}/windows/installer-windows.wxs"

resources/install/windows/installer-windows.wxs

@@ -2,7 +2,7 @@
 <Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">
 
 <Product
-    Id="*"
+    Id="@WIX_PRODUCT_ID@"
     Language="1033"
     Manufacturer="@APP_NAME@"
     Name="@APP_NAME@"