diff --git a/FFUDevelopment/BuildFFUVM_UI.xaml b/FFUDevelopment/BuildFFUVM_UI.xaml
index 1d73906..8551fb0 100644
--- a/FFUDevelopment/BuildFFUVM_UI.xaml
+++ b/FFUDevelopment/BuildFFUVM_UI.xaml
@@ -223,16 +223,24 @@
             <!-- TAB: Windows Settings -->
             <ScrollViewer x:Name="pageWindows" VerticalScrollBarVisibility="Auto" Visibility="Collapsed">
                     <StackPanel Margin="16">
-                        <!-- Windows ISO Path -->
-                        <TextBlock Text="Windows ISO Path" Margin="0,0,0,4" ToolTip="Path to the Windows ISO file."/>
-                        <Grid Margin="0,0,0,24">
-                            <Grid.ColumnDefinitions>
-                                <ColumnDefinition Width="*"/>
-                                <ColumnDefinition Width="Auto"/>
-                            </Grid.ColumnDefinitions>
-                            <TextBox x:Name="txtISOPath" Grid.Column="0" VerticalAlignment="Center" HorizontalAlignment="Stretch" ToolTip="Path to the Windows ISO file."/>
-                            <Button x:Name="btnBrowseISO" Grid.Column="1" Content="Browse..." Padding="12,4" Margin="8,0,0,0" VerticalAlignment="Center"/>
-                        </Grid>
+                        <!-- Windows Media Source -->
+                        <TextBlock Text="Windows Media Source" Margin="0,0,0,8" ToolTip="Choose whether to download Windows ESD from Microsoft or provide your own Windows ISO file."/>
+                        <StackPanel x:Name="cmbWindowsMediaSource" Margin="0,0,0,24">
+                            <RadioButton x:Name="rbDownloadESD" Content="Download Windows ESD" IsChecked="True" Margin="0,0,0,8" GroupName="WindowsMediaSource" ToolTip="Download the latest Windows ESD file from Microsoft."/>
+                            <RadioButton x:Name="rbProvideISO" Content="Provide Windows ISO" Margin="0" GroupName="WindowsMediaSource" ToolTip="Use your own Windows ISO file."/>
+                        </StackPanel>
+                        <!-- Windows ISO Path (visible only when "Provide Windows ISO" is selected) -->
+                        <StackPanel x:Name="isoPathPanel" Visibility="Collapsed">
+                            <TextBlock Text="Windows ISO Path" Margin="0,0,0,4" ToolTip="Path to the Windows ISO file."/>
+                            <Grid Margin="0,0,0,24">
+                                <Grid.ColumnDefinitions>
+                                    <ColumnDefinition Width="*"/>
+                                    <ColumnDefinition Width="Auto"/>
+                                </Grid.ColumnDefinitions>
+                                <TextBox x:Name="txtISOPath" Grid.Column="0" VerticalAlignment="Center" HorizontalAlignment="Stretch" ToolTip="Path to the Windows ISO file."/>
+                                <Button x:Name="btnBrowseISO" Grid.Column="1" Content="Browse..." Padding="12,4" Margin="8,0,0,0" VerticalAlignment="Center"/>
+                            </Grid>
+                        </StackPanel>
                         <!-- Windows Release -->
                         <TextBlock Text="Windows Release" Margin="0,0,0,4" ToolTip="Integer value of 10 or 11. This is used to identify which release of Windows to download. Default is 11."/>
                         <ComboBox x:Name="cmbWindowsRelease" HorizontalAlignment="Stretch" Margin="0,0,0,24" ToolTip="Integer value of 10 or 11. This is used to identify which release of Windows to download. Default is 11."/>
diff --git a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Config.psm1 b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Config.psm1
index e540e31..4224a55 100644
--- a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Config.psm1
+++ b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Config.psm1
@@ -54,6 +54,7 @@ function Get-UIConfig {
         InstallOffice                  = $State.Controls.chkInstallOffice.IsChecked
         InstallWingetApps              = $State.Controls.chkInstallWingetApps.IsChecked
         ISOPath                        = $State.Controls.txtISOPath.Text
+        WindowsMediaSource             = if ($null -ne $State.Controls.rbProvideISO -and $State.Controls.rbProvideISO.IsChecked) { "Provide Windows ISO" } else { "Download Windows ESD" }
         LogicalSectorSizeBytes         = [int]$State.Controls.cmbLogicalSectorSize.SelectedItem.Content
         # Make                           = $null
         MediaType                      = $State.Controls.cmbMediaType.SelectedItem
@@ -486,6 +487,15 @@ function Update-UIFromConfig {
 
     # Windows Settings
     Set-UIValue -ControlName 'txtISOPath' -PropertyName 'Text' -ConfigObject $ConfigContent -ConfigKey 'ISOPath' -State $State
+    # Load Windows Media Source setting
+    if ($null -ne $ConfigContent.PSObject.Properties.Item('WindowsMediaSource')) {
+        if ($ConfigContent.WindowsMediaSource -eq 'Provide Windows ISO') {
+            $State.Controls.rbProvideISO.IsChecked = $true
+        }
+        else {
+            $State.Controls.rbDownloadESD.IsChecked = $true
+        }
+    }
     
     # Special handling for Windows Release and SKU due to value collision (e.g., 2019 for Server and LTSC)
     if (($null -ne $ConfigContent.PSObject.Properties.Item('WindowsRelease')) -and ($null -ne $ConfigContent.PSObject.Properties.Item('WindowsSKU'))) {
diff --git a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1 b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
index ec9229c..1e15417 100644
--- a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
+++ b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Handlers.psm1
@@ -392,12 +392,31 @@ function Register-EventHandlers {
         })
 
     # Windows Settings tab Event Handlers
-    $State.Controls.txtISOPath.Add_TextChanged({
-            param($eventSource, $textChangedEventArgs)
-            $window = [System.Windows.Window]::GetWindow($eventSource)
-            $localState = $window.Tag
-            Get-WindowsSettingsCombos -isoPath $localState.Controls.txtISOPath.Text -State $localState
-        })
+    # Windows Media Source radio buttons
+    if ($null -ne $State.Controls.rbProvideISO) {
+        $State.Controls.rbProvideISO.Add_Checked({
+                param($eventSource, $routedEventArgs)
+                $window = [System.Windows.Window]::GetWindow($eventSource)
+                if ($null -eq $window -or $null -eq $window.Tag) { return }
+                $localState = $window.Tag
+                $localState.Controls.isoPathPanel.Visibility = 'Visible'
+                # Use a placeholder .iso path to trigger ISO mode even before a real path is provided
+                $isoPath = $localState.Controls.txtISOPath.Text
+                if ([string]::IsNullOrWhiteSpace($isoPath)) {
+                    $isoPath = 'placeholder.iso'
+                }
+                Get-WindowsSettingsCombos -isoPath $isoPath -State $localState
+            })
+        $State.Controls.rbProvideISO.Add_Unchecked({
+                param($eventSource, $routedEventArgs)
+                $window = [System.Windows.Window]::GetWindow($eventSource)
+                if ($null -eq $window -or $null -eq $window.Tag) { return }
+                $localState = $window.Tag
+                $localState.Controls.isoPathPanel.Visibility = 'Collapsed'
+                $localState.Controls.txtISOPath.Text = ''
+                Get-WindowsSettingsCombos -isoPath '' -State $localState
+            })
+    }
 
     $State.Controls.cmbWindowsRelease.Add_SelectionChanged({
             param($eventSource, $selectionChangedEventArgs)
@@ -407,7 +426,13 @@ function Register-EventHandlers {
             if ($null -ne $localState.Controls.cmbWindowsRelease.SelectedItem) {
                 $selectedReleaseValue = $localState.Controls.cmbWindowsRelease.SelectedItem.Value
             }
-            Update-WindowsVersionCombo -selectedRelease $selectedReleaseValue -isoPath $localState.Controls.txtISOPath.Text -State $localState
+            # Determine ISO path based on radio button state
+            $isoPath = ''
+            if ($null -ne $localState.Controls.rbProvideISO -and $localState.Controls.rbProvideISO.IsChecked) {
+                $isoPath = $localState.Controls.txtISOPath.Text
+                if ([string]::IsNullOrWhiteSpace($isoPath)) { $isoPath = 'placeholder.iso' }
+            }
+            Update-WindowsVersionCombo -selectedRelease $selectedReleaseValue -isoPath $isoPath -State $localState
             Update-WindowsSkuCombo -State $localState
             Update-WindowsArchCombo -State $localState
 
diff --git a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Initialize.psm1 b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Initialize.psm1
index 929165a..ed65029 100644
--- a/FFUDevelopment/FFUUI.Core/FFUUI.Core.Initialize.psm1
+++ b/FFUDevelopment/FFUUI.Core/FFUUI.Core.Initialize.psm1
@@ -112,6 +112,9 @@ function Initialize-UIControls {
     $State.Controls.cmbWindowsRelease = $window.FindName('cmbWindowsRelease')
     $State.Controls.cmbWindowsVersion = $window.FindName('cmbWindowsVersion')
     $State.Controls.txtISOPath = $window.FindName('txtISOPath')
+    $State.Controls.rbDownloadESD = $window.FindName('rbDownloadESD')
+    $State.Controls.rbProvideISO = $window.FindName('rbProvideISO')
+    $State.Controls.isoPathPanel = $window.FindName('isoPathPanel')
     $State.Controls.btnBrowseISO = $window.FindName('btnBrowseISO')
     $State.Controls.cmbWindowsArch = $window.FindName('cmbWindowsArch')
     $State.Controls.cmbWindowsLang = $window.FindName('cmbWindowsLang')
@@ -389,7 +392,12 @@ function Initialize-UIDefaults {
     $State.Controls.cmbLogicalSectorSize.SelectedItem = ($State.Controls.cmbLogicalSectorSize.Items | Where-Object { $_.Content -eq $State.Defaults.generalDefaults.LogicalSectorSize.ToString() })
    
     # Populate Windows Release, Version, and SKU comboboxes
-    Get-WindowsSettingsCombos -isoPath $State.Defaults.windowsSettingsDefaults.DefaultISOPath -State $State
+    # Initialize Windows settings combos based on media source mode
+    $initIsoPath = $State.Defaults.windowsSettingsDefaults.DefaultISOPath
+    if ($null -ne $State.Controls.rbProvideISO -and -not $State.Controls.rbProvideISO.IsChecked) {
+        $initIsoPath = ''
+    }
+    Get-WindowsSettingsCombos -isoPath $initIsoPath -State $State
     
     # Windows Settings tab defaults
     $State.Controls.cmbWindowsLang.ItemsSource = $State.Defaults.windowsSettingsDefaults.AllowedLanguages
diff --git a/FFUDevelopment/config/Sample_default.json b/FFUDevelopment/config/Sample_default.json
index dfe49aa..e8b1e6a 100644
Binary files a/FFUDevelopment/config/Sample_default.json and b/FFUDevelopment/config/Sample_default.json differ