diff --git a/lib/images/windows/templates/generalize.nix b/lib/images/windows/templates/generalize.nix
index 3e43a93..3b4d3fe 100644
--- a/lib/images/windows/templates/generalize.nix
+++ b/lib/images/windows/templates/generalize.nix
@@ -336,6 +336,17 @@ in {
     del /q C:\Windows\Panther\unattend.xml 2>nul
     del /q C:\Windows\Panther\Unattend\unattend.xml 2>nul
     del /q C:\Windows\System32\Sysprep\Panther\unattend.xml 2>nul
+    ${lib.optionalString (dataDisk != null) ''
+    :: Lay the data disk out here, in Audit Mode, rather than leaving it to the
+    :: specialize pass alone. Component order within a pass is not guaranteed,
+    :: and FolderLocations is applied by Shell-Setup while the disk is prepared
+    :: by Deployment -- so relocation can be evaluated before the volume it
+    :: names exists, which silently leaves profiles on C:. Audit Mode is a
+    :: fully booted OS with the disk already attached, so this always works.
+    :: The specialize copy stays as a letter re-assertion after generalize
+    :: clears MountedDevices.
+    call C:\vmix-init-data-disk.cmd
+    ''}
     C:\Windows\System32\Sysprep\sysprep.exe /generalize /oobe ${if delayOobeRun then "/shutdown" else "/reboot"} /quiet /unattend:C:\oobe-unattend.xml
   '';
 }