diff --git a/source/Cosmos.Build.Windows/Builder/Builder.cs b/source/Cosmos.Build.Windows/Builder/Builder.cs
index 92080cff7..87e2bb405 100644
--- a/source/Cosmos.Build.Windows/Builder/Builder.cs
+++ b/source/Cosmos.Build.Windows/Builder/Builder.cs
@@ -29,8 +29,8 @@ namespace Cosmos.Compiler.Builder
         public event Action<BuildProgress> BuildProgress;
         public event Action<LogSeverityEnum, string> LogMessage;
 
-        private DebugWindow xDebugWindow = null; //HACK pass in event
-        public DebugWindow DebugWindow { get { return xDebugWindow; } }
+        private DebugWindowController xDebugWindow = null; //HACK pass in event
+        public DebugWindowController DebugWindow { get { return xDebugWindow; } }
 
 
         private readonly BuildProgress currentProgress = new BuildProgress();
@@ -305,7 +305,7 @@ namespace Cosmos.Compiler.Builder
         }
 
 
-        private void ProcessDebug(BuildOptions options, ref DebugWindow xDebugWindow, ref Process xQEMU)
+        private void ProcessDebug(BuildOptions options, ref DebugWindowController xDebugWindow, ref Process xQEMU)
         {
 
             if (options.DebugMode == DebugMode.Source)
@@ -377,9 +377,10 @@ namespace Cosmos.Compiler.Builder
 
                 }
 
-                //HACK MUST BE UI
-                //xDebugWindow = new DebugWindow();
-                //xDebugWindow.SetSourceInfoMap(xSourceMappings, xDebugConnector);
+                //TODO handle passing to UI better
+                xDebugWindow = new DebugWindowController();
+                xDebugWindow.mSourceMappings = xSourceMappings; 
+                xDebugWindow.mDebugConnector = xDebugConnector;
             }
             else
             {
diff --git a/source/Cosmos.Build.Windows/Builder/IBuilder.cs b/source/Cosmos.Build.Windows/Builder/IBuilder.cs
index 72cd946f0..fe3db5c0a 100644
--- a/source/Cosmos.Build.Windows/Builder/IBuilder.cs
+++ b/source/Cosmos.Build.Windows/Builder/IBuilder.cs
@@ -19,7 +19,7 @@ namespace Cosmos.Compiler.Builder
 
         string BuildPath {get;}
 
-        DebugWindow DebugWindow {get;}   //HACK pass in event
+        DebugWindowController DebugWindow { get; }   //HACK pass in event
 
 
         //string[] GetPlugs();
diff --git a/source/Cosmos.Build.Windows/Cosmos.Compiler.Builder.csproj b/source/Cosmos.Build.Windows/Cosmos.Compiler.Builder.csproj
index 07ea4eddd..6320e6e0b 100644
--- a/source/Cosmos.Build.Windows/Cosmos.Compiler.Builder.csproj
+++ b/source/Cosmos.Build.Windows/Cosmos.Compiler.Builder.csproj
@@ -155,6 +155,7 @@
       <DependentUpon>DebugWindow.xaml</DependentUpon>
       <SubType>Code</SubType>
     </Compile>
+    <Compile Include="UI\DebugWindowController.cs" />
     <Compile Include="UI\IBuildProgressUC.cs">
       <SubType>Code</SubType>
     </Compile>
diff --git a/source/Cosmos.Build.Windows/UI/DebugWindowController.cs b/source/Cosmos.Build.Windows/UI/DebugWindowController.cs
new file mode 100644
index 000000000..29709e229
--- /dev/null
+++ b/source/Cosmos.Build.Windows/UI/DebugWindowController.cs
@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Cosmos.Compiler.Builder
+{
+    public class DebugWindowController
+    {
+        private DebugWindow window;
+
+        public SourceInfos mSourceMappings { get; set; } 
+        public DebugConnector mDebugConnector {get; set; } 
+
+        public void Show()
+        {
+            window = new DebugWindow(); 
+                window.SetSourceInfoMap(mSourceMappings ,mDebugConnector);
+            window.Show(); 
+
+        }
+    }
+}
diff --git a/source/Cosmos.Build.Windows/UI/MainWindowController.cs b/source/Cosmos.Build.Windows/UI/MainWindowController.cs
index dd84254d0..b5e726ff4 100644
--- a/source/Cosmos.Build.Windows/UI/MainWindowController.cs
+++ b/source/Cosmos.Build.Windows/UI/MainWindowController.cs
@@ -92,24 +92,32 @@ namespace Cosmos.Compiler.Builder
 
         void mBuilder_BuildCompleted()
         {
+            mainWindow.Dispatcher.Invoke(new Action(PostBuildUI)); 
+           
+
+            mainWindow.ThreadedClose();  //HACK //TODO consider making the controller survive the window. 
+        }
+
+
+        void PostBuildUI()
+        {
+
             new ConsoleWindow().HideWindow();
 
             //HACK need to fire Debugger window in event 
 
             // Problems around with DebugWindow getting stuck, this seems to work
             //mMainWindow.Hide();
-            if (mBuilder.DebugWindow!= null)
+            if (mBuilder.DebugWindow != null)
             {
                 // Beginnings of experiment to host QEMU
                 //if (xQEMU != null) {
                 //    IntPtr xDbgHandle = new WindowInteropHelper(Application.Current.MainWindow).Handle;
                 //    SetParent(xQEMU.MainWindowHandle, xDbgHandle);
                 //}
-                mBuilder.DebugWindow.ShowDialog();
+                mBuilder.DebugWindow.Show();
             }
             //mMainWindow.Close();
-
-            mainWindow.ThreadedClose();  //HACK //TODO consider making the controller survive the window. 
         }