diff --git a/xpfe/components/prefwindow/resources/content/Makefile.in b/xpfe/components/prefwindow/resources/content/Makefile.in
index 0ad285c185d..24fafc93386 100644
--- a/xpfe/components/prefwindow/resources/content/Makefile.in
+++ b/xpfe/components/prefwindow/resources/content/Makefile.in
@@ -26,6 +26,8 @@ VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+DIRS		= unix
+
 CHROME_DIR = packages/core
 CHROME_CONTENT_DIR = communicator/content/pref
 
diff --git a/xpfe/components/prefwindow/resources/content/mac/MANIFEST b/xpfe/components/prefwindow/resources/content/mac/MANIFEST
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/xpfe/components/prefwindow/resources/content/mac/platformPrefOverlay.xul b/xpfe/components/prefwindow/resources/content/mac/platformPrefOverlay.xul
new file mode 100644
index 00000000000..4383f171b14
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/content/mac/platformPrefOverlay.xul
@@ -0,0 +1,34 @@
+<?xml version="1.0"?>
+
+<!--
+   The contents of this file are subject to the Netscape Public
+   License Version 1.1 (the "License"); you may not use this file
+   except in compliance with the License. You may obtain a copy of
+   the License at http://www.mozilla.org/NPL/
+    
+   Software distributed under the License is distributed on an "AS
+   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+   implied. See the License for the specific language governing
+   rights and limitations under the License.
+    
+   The Original Code is Mozilla Communicator client code, released
+   March 31, 1998.
+   
+   The Initial Developer of the Original Code is Netscape
+   Communications Corporation. Portions created by Netscape are
+   Copyright (C) 1998-1999 Netscape Communications Corporation. All
+   Rights Reserved.
+   
+   Contributor(s): 
+     Ben Goodger <ben@netscape.com>
+  -->
+
+<overlay id="platformPreferencesOverlay"
+         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+  
+  <!-- the poor macintosh doesnt support any of the extra goodies that unix and 
+       windows do, so this file is blank. (that doesn't mean it's not required,
+       so don't remove it!) -->
+         
+</overlay>
+
diff --git a/xpfe/components/prefwindow/resources/content/makefile.win b/xpfe/components/prefwindow/resources/content/makefile.win
index 25d202fe339..03c07a7da10 100644
--- a/xpfe/components/prefwindow/resources/content/makefile.win
+++ b/xpfe/components/prefwindow/resources/content/makefile.win
@@ -21,6 +21,8 @@
 
 DEPTH=..\..\..\..\..
 
+DIRS= win
+
 CHROME_DIR = packages\core
 CHROME_CONTENT_DIR = communicator\content\pref
 
diff --git a/xpfe/components/prefwindow/resources/content/pref-colors.xul b/xpfe/components/prefwindow/resources/content/pref-colors.xul
index a39df04a523..c58d2978f6a 100644
--- a/xpfe/components/prefwindow/resources/content/pref-colors.xul
+++ b/xpfe/components/prefwindow/resources/content/pref-colors.xul
@@ -19,10 +19,12 @@
    Rights Reserved.
    
    Contributor(s): 
+     Ben Goodger <ben@netscape.com>
   -->
 
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 <?xul-overlay href="chrome://global/content/dialogOverlay.xul"?>
+<?xul-overlay href="chrome://communicator/content/pref/platformPrefOverlay.xul"?>
 
 <!DOCTYPE window SYSTEM "chrome://communicator/locale/pref/pref-colors.dtd" >
 
@@ -35,7 +37,7 @@
 
   <script language="JavaScript">
   <![CDATA[
-    _elementIDs = ["foregroundText", "background", "browserUseWindowsColors", "unvisitedLinks", "visitedLinks", "browserUnderlineAnchors", "browserUseDocumentColors"];
+    _elementIDs = ["foregroundText", "background", "unvisitedLinks", "visitedLinks", "browserUnderlineAnchors", "browserUseDocumentColors"];
   ]]>
   </script>
   
@@ -44,7 +46,7 @@
   <box class="box-smallheader" title="&lHeader;"/>
 
   <box>
-		<titledbox orient="vertical" flex="1">
+		<titledbox orient="vertical" flex="1" id="pageColours">
 			<title><text value="&color;"/></title>
       <box>
         <text class="label" value="&textColor.label;" accesskey="&textColor.accesskey;" for="foregroundtextmenu"/>
@@ -70,8 +72,8 @@
         </menu>
         <data id="background" pref="true" preftype="color" prefstring="browser.display.background_color" prefattribute="value" wsm_attributes="value"/>
       </box>
-      <checkbox id="browserUseWindowsColors" value="&useWindowsColors.label;" accesskey="&useWindowsColors.accesskey;"
-                pref="true" preftype="bool" prefstring="browser.display.wfe.use_windows_colors" prefattribute="checked"/>
+      <separator class="thin"/>
+      <box autostretch="never" id="useWindowsColoursBox"/>
     </titledbox>
       
     <titledbox orient="vertical" flex="1">
@@ -100,8 +102,11 @@
         </menu>
         <data id="visitedLinks" pref="true" preftype="string" prefstring="browser.visited_color" prefattribute="value" wsm_attributes="value"/>
       </box>
-  		<checkbox id="browserUnderlineAnchors" value="&underlineLinks.label;" accesskey="&underlineLinks.accesskey;"
-                pref="true" preftype="bool" prefstring="browser.underline_anchors" prefattribute="checked"/>
+      <separator class="thin"/>
+      <box autostretch="never">
+    		<checkbox id="browserUnderlineAnchors" value="&underlineLinks.label;" accesskey="&underlineLinks.accesskey;"
+                  pref="true" preftype="bool" prefstring="browser.underline_anchors" prefattribute="checked"/>
+      </box>
     </titledbox>
   </box>
   
diff --git a/xpfe/components/prefwindow/resources/content/preftree.xul b/xpfe/components/prefwindow/resources/content/preftree.xul
index 8cdcc286075..91022edf917 100644
--- a/xpfe/components/prefwindow/resources/content/preftree.xul
+++ b/xpfe/components/prefwindow/resources/content/preftree.xul
@@ -20,8 +20,10 @@
    Rights Reserved.
    
    Contributor(s): 
+     Ben Goodger <ben@netscape.com>
   -->
 
+<?xul-overlay href="chrome://communicator/content/pref/platformPrefOverlay.xul"?>
 
 <!DOCTYPE window SYSTEM "chrome://communicator/locale/pref/preftree.dtd" >
 
@@ -43,8 +45,6 @@
   </treehead>
 
   <treechildren id="panelChildren" flex="1">
-
-    
     <treeitem container="true" open="true" id="appearance">
       <treerow>   
         <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-appearance.xul" value="&appear.label;"/> 
@@ -137,21 +137,6 @@
       </treerow>
     </treeitem>
 
-    <!-- 
-    <treeitem open="true" id="offline">
-      <treerow>       
-        <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-offline.xul" value="&offline.label;"/> 
-      </treerow>
-      <treechildren>
-        <treeitem>
-          <treerow>
-            <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-download.xul" value="&down.label;"/> 
-          </treerow>
-        </treeitem>
-      </treechildren>
-    </treeitem>  
-    -->
-    
     <treeitem container="true" open="true" id="advancedItem">
       <treerow>
         <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-advanced.xul" value="&advance.label;"/> 
@@ -179,17 +164,6 @@
             <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-proxies.xul" value="&proxies.label;"/> 
           </treerow>
         </treeitem>
-        <treeitem id="mousewheelItem">
-          <treerow>
-            <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-mousewheel.xul" value="&mousewheel.label;"/>
-          </treerow>
-        </treeitem>
-        <treeitem id="winhooks">
-          <treerow>
-            <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-winhooks.xul" value="&winhooks.label;"/>
-          </treerow>
-        </treeitem>
-
       </treechildren>
     </treeitem>
 
diff --git a/xpfe/components/prefwindow/resources/content/unix/Makefile.in b/xpfe/components/prefwindow/resources/content/unix/Makefile.in
new file mode 100644
index 00000000000..a0a11639218
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/content/unix/Makefile.in
@@ -0,0 +1,37 @@
+#
+# The contents of this file are subject to the Netscape Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/NPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is mozilla.org code.
+#
+# The Initial Developer of the Original Code is Netscape
+# Communications Corporation.  Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation. All
+# Rights Reserved.
+#
+# Contributor(s): 
+#
+
+DEPTH		= ../../../../../..
+topsrcdir	= @top_srcdir@
+srcdir		= @srcdir@
+VPATH		= @srcdir@
+
+include $(DEPTH)/config/autoconf.mk
+
+CHROME_DIR = packages/core
+CHROME_CONTENT_DIR = communicator/content/pref
+
+CHROME_CONTENT = \
+		platformPrefOverlay.xul \
+		$(NULL)
+
+include $(topsrcdir)/config/rules.mk
+
diff --git a/xpfe/components/prefwindow/resources/content/unix/platformPrefOverlay.xul b/xpfe/components/prefwindow/resources/content/unix/platformPrefOverlay.xul
new file mode 100644
index 00000000000..f025d494b60
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/content/unix/platformPrefOverlay.xul
@@ -0,0 +1,41 @@
+<?xml version="1.0"?>
+
+<!--
+   The contents of this file are subject to the Netscape Public
+   License Version 1.1 (the "License"); you may not use this file
+   except in compliance with the License. You may obtain a copy of
+   the License at http://www.mozilla.org/NPL/
+    
+   Software distributed under the License is distributed on an "AS
+   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+   implied. See the License for the specific language governing
+   rights and limitations under the License.
+    
+   The Original Code is Mozilla Communicator client code, released
+   March 31, 1998.
+   
+   The Initial Developer of the Original Code is Netscape
+   Communications Corporation. Portions created by Netscape are
+   Copyright (C) 1998-1999 Netscape Communications Corporation. All
+   Rights Reserved.
+   
+   Contributor(s): 
+     Ben Goodger <ben@netscape.com>
+  -->
+
+<!DOCTYPE window SYSTEM "chrome://communicator/locale/pref/platformPrefOverlay.dtd">  
+  
+<overlay id="platformPreferencesOverlay"
+         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <!-- Mousewheel support is only enabled on Windows and Unix -->
+  <treechildren id="advancedChildren">
+    <treeitem id="mousewheelItem">
+      <treerow>
+        <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-mousewheel.xul" value="&mousewheel.label;"/>
+      </treerow>
+    </treeitem>
+  </treechildren>
+         
+</overlay>
+
diff --git a/xpfe/components/prefwindow/resources/content/win/makefile.win b/xpfe/components/prefwindow/resources/content/win/makefile.win
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/xpfe/components/prefwindow/resources/content/win/platformPrefOverlay.xul b/xpfe/components/prefwindow/resources/content/win/platformPrefOverlay.xul
new file mode 100644
index 00000000000..90009097172
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/content/win/platformPrefOverlay.xul
@@ -0,0 +1,62 @@
+<?xml version="1.0"?>
+
+<!--
+   The contents of this file are subject to the Netscape Public
+   License Version 1.1 (the "License"); you may not use this file
+   except in compliance with the License. You may obtain a copy of
+   the License at http://www.mozilla.org/NPL/
+    
+   Software distributed under the License is distributed on an "AS
+   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+   implied. See the License for the specific language governing
+   rights and limitations under the License.
+    
+   The Original Code is Mozilla Communicator client code, released
+   March 31, 1998.
+   
+   The Initial Developer of the Original Code is Netscape
+   Communications Corporation. Portions created by Netscape are
+   Copyright (C) 1998-1999 Netscape Communications Corporation. All
+   Rights Reserved.
+   
+   Contributor(s): 
+     Ben Goodger <ben@netscape.com>
+  -->
+
+<!DOCTYPE window SYSTEM "chrome://communicator/locale/pref/platformPrefOverlay.dtd">  
+  
+<overlay id="platformPreferencesOverlay"
+         xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <script language="JavaScript">
+  <![CDATA[
+    dump("*** in platformPrefOverlay for windows\n");
+    if (_elementIDs != undefined)
+      _elementIDs.push("browserUseWindowsColors");
+  ]]>
+  </script>         
+
+  <!-- "Use Windows Colours" checkbox on colours panel applies only
+       to Windows! -->         
+  <box id="useWindowsColoursBox">
+    <checkbox id="browserUseWindowsColors" value="&useWindowsColors.label;" accesskey="&useWindowsColors.accesskey;"
+            pref="true" preftype="bool" prefstring="browser.display.wfe.use_windows_colors" prefattribute="checked"/>
+  </box>
+
+  <!-- Mousewheel support is only enabled on Windows and Unix, and Windows
+       integration is (obviously) only applicable on Windows. -->
+  <treechildren id="advancedChildren">
+    <treeitem id="mousewheelItem">
+      <treerow>
+        <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-mousewheel.xul" value="&mousewheel.label;"/>
+      </treerow>
+    </treeitem>
+    <treeitem id="winhooks">
+      <treerow>
+        <treecell class="treecell-indent" url="chrome://communicator/content/pref/pref-winhooks.xul" value="&winhooks.label;"/>
+      </treerow>
+    </treeitem>  
+  </treechildren>
+         
+</overlay>
+
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/Makefile.in b/xpfe/components/prefwindow/resources/locale/en-US/Makefile.in
index 11081942d84..8fa63f6f37e 100644
--- a/xpfe/components/prefwindow/resources/locale/en-US/Makefile.in
+++ b/xpfe/components/prefwindow/resources/locale/en-US/Makefile.in
@@ -26,6 +26,8 @@ VPATH		= @srcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
+DIRS		= unix
+
 CHROME_DIR = locales/en-US
 CHROME_L10N_DIR = communicator/locale/pref
 
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/makefile.win b/xpfe/components/prefwindow/resources/locale/en-US/makefile.win
index 3e07037a2dc..520780b7c53 100644
--- a/xpfe/components/prefwindow/resources/locale/en-US/makefile.win
+++ b/xpfe/components/prefwindow/resources/locale/en-US/makefile.win
@@ -21,6 +21,8 @@
 
 DEPTH=..\..\..\..\..\..
 
+DIRS = win
+
 CHROME_DIR = locales\en-US
 CHROME_L10N_DIR = communicator\locale\pref
 
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/pref-colors.dtd b/xpfe/components/prefwindow/resources/locale/en-US/pref-colors.dtd
index fad3441a791..ab8ff2af270 100644
--- a/xpfe/components/prefwindow/resources/locale/en-US/pref-colors.dtd
+++ b/xpfe/components/prefwindow/resources/locale/en-US/pref-colors.dtd
@@ -8,8 +8,6 @@
 <!ENTITY  textColor.accesskey             "t">
 <!ENTITY  backgroundColor.label           "Background:">
 <!ENTITY  backgroundColor.accesskey       "b">
-<!ENTITY  useWindowsColors.label          "Use Windows colors">
-<!ENTITY  useWindowsColors.accesskey      "w">
 
 <!ENTITY  underlineLinks.label            "Underline links">
 <!ENTITY  underlineLinks.accesskey        "u">
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/preftree.dtd b/xpfe/components/prefwindow/resources/locale/en-US/preftree.dtd
index 6fbefdb9ed5..7699e3e0164 100644
--- a/xpfe/components/prefwindow/resources/locale/en-US/preftree.dtd
+++ b/xpfe/components/prefwindow/resources/locale/en-US/preftree.dtd
@@ -26,7 +26,5 @@
 <!ENTITY proxies.label "Proxies">
 <!ENTITY smart.label "Software Installation">
 <!ENTITY debug.label "Debug">
-<!ENTITY mousewheel.label "Mouse Wheel">
-<!ENTITY winhooks.label "Desktop Integration">
 <!ENTITY search.label "Internet Search">
 <!ENTITY policies.label "Security Policies">
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/unix/Makefile.in b/xpfe/components/prefwindow/resources/locale/en-US/unix/Makefile.in
new file mode 100644
index 00000000000..de27308a933
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/locale/en-US/unix/Makefile.in
@@ -0,0 +1,37 @@
+#
+# The contents of this file are subject to the Netscape Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/NPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is mozilla.org code.
+#
+# The Initial Developer of the Original Code is Netscape
+# Communications Corporation.  Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation. All
+# Rights Reserved.
+#
+# Contributor(s): 
+#
+
+DEPTH		= ../../../../../../..
+topsrcdir	= @top_srcdir@
+srcdir		= @srcdir@
+VPATH		= @srcdir@
+
+include $(DEPTH)/config/autoconf.mk
+
+CHROME_DIR = locales/en-US
+CHROME_L10N_DIR = communicator/locale/pref
+
+CHROME_L10N = \
+		platformPrefOverlay.dtd \
+		$(NULL)
+
+include $(topsrcdir)/config/rules.mk
+
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/unix/platformPrefOverlay.dtd b/xpfe/components/prefwindow/resources/locale/en-US/unix/platformPrefOverlay.dtd
new file mode 100644
index 00000000000..c532a9bd8af
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/locale/en-US/unix/platformPrefOverlay.dtd
@@ -0,0 +1 @@
+<!ENTITY mousewheel.label "Mouse Wheel">
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/win/makefile.win b/xpfe/components/prefwindow/resources/locale/en-US/win/makefile.win
new file mode 100644
index 00000000000..55028082637
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/locale/en-US/win/makefile.win
@@ -0,0 +1,32 @@
+#!nmake
+#
+# The contents of this file are subject to the Netscape Public
+# License Version 1.1 (the "License"); you may not use this file
+# except in compliance with the License. You may obtain a copy of
+# the License at http://www.mozilla.org/NPL/
+#
+# Software distributed under the License is distributed on an "AS
+# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# rights and limitations under the License.
+#
+# The Original Code is mozilla.org code.
+#
+# The Initial Developer of the Original Code is Netscape
+# Communications Corporation.  Portions created by Netscape are
+# Copyright (C) 1998 Netscape Communications Corporation. All
+# Rights Reserved.
+#
+# Contributor(s): 
+
+DEPTH=..\..\..\..\..\..\..
+
+CHROME_DIR = locales\en-US
+CHROME_L10N_DIR = communicator\locale\pref
+
+CHROME_L10N = \
+	.\platformPrefOverlay.dtd \
+	$(NULL)
+
+include <$(DEPTH)\config\rules.mak>
+
diff --git a/xpfe/components/prefwindow/resources/locale/en-US/win/platformPrefOverlay.dtd b/xpfe/components/prefwindow/resources/locale/en-US/win/platformPrefOverlay.dtd
new file mode 100644
index 00000000000..79587027395
--- /dev/null
+++ b/xpfe/components/prefwindow/resources/locale/en-US/win/platformPrefOverlay.dtd
@@ -0,0 +1,5 @@
+<!ENTITY  useWindowsColors.label          "Use Windows colors">
+<!ENTITY  useWindowsColors.accesskey      "w">
+<!ENTITY mousewheel.label                 "Mouse Wheel">
+<!ENTITY winhooks.label                   "Desktop Integration">
+