diff --git a/CLAUDE.md b/CLAUDE.md
index e4668dc2..588f7d42 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -1050,9 +1050,15 @@ fullscreen.** The main display takes it; every secondary panel is refused. XP al
 - Device index → physical monitor is **1:1** on this bench (colour test confirmed): main=0,
   radar=1, mfd-left=2, mfd-right=3, so `-tmon 1,2,3,4` is identical to auto-detection.
 - **Confirmed working end-to-end: all three secondary panels present, full mission played.**
-- ⚠️ **The working `dgVoodoo.conf` is NOT versioned in the repo** (it was removed in `0ceba9c7`).
-  A fresh deploy will reproduce the silent MFD failure. TODO: commit it + have `deploy-mw4.ps1`
-  place it.
+- ⚠️ **dgVoodoo2 is deliberately NOT in the repo and must NOT be — it breaks Windows XP
+  deployments.** The pod fleet is mixed: XP pods need native DirectDraw and nothing else, while
+  Win10/11 pods need dgVoodoo2 for any MFD mode. Shipping it in the build (or having
+  `deploy-mw4.ps1` place it) would push a Win10-only dependency onto XP machines and break them.
+  It stays an **installed-per-machine, OS-dependent prerequisite** set up by the pod owner on
+  Win10/11 only. `dgVoodoo.conf`/`dgVoodooCpl.exe` were removed in `0ceba9c7` for this reason —
+  do not "fix" that by re-adding them. The required setting (Scaling mode
+  `Stretched, Keep Aspect Ratio`, on the **General** tab) is documented in the pod-owner release
+  notes instead.
 
 ### 📐 Engine is 4:3 ONLY (relevant to every display decision)
 `ImageHlp.cpp:~464` asserts the complete supported resolution set: **640x480, 512x384, 800x600,
@@ -1101,10 +1107,10 @@ Smaller than it sounds because the mechanisms already exist:
   DISPLAY AND VIDEO).
 
 ## Next steps (proposed)
-- [ ] **Commit the working `dgVoodoo.conf`** and have `deploy-mw4.ps1` place it — without it a
-  fresh 4-monitor deploy silently fails (see STEP 10).
 - [ ] (Decision pending) Borderless-windowed migration — see the staged assessment in STEP 10.
-  Step 2 (one panel) is the cheap, decisive experiment.
+  Step 2 (one panel) is the cheap, decisive experiment. Note this is the only route that would
+  remove the dgVoodoo2 prerequisite **without** breaking the XP pods, since it needs no external
+  DLL on either OS.
 - [ ] Test a **full mission windowed** (only the console/shell has been verified windowed).
 - [x] ~~Windowed 3D viewport on Win11~~ — DONE via DDrawCompat (see STEP 8 viewport section).
 - [ ] (Optional) Curate remaining WIP content as features are exercised (editor loads dev `Content\`).
diff --git a/RELEASE-NOTES-5.1.0b_RC1.html b/RELEASE-NOTES-5.1.0b_RC1.html
index a8284b3d..ede008a4 100644
--- a/RELEASE-NOTES-5.1.0b_RC1.html
+++ b/RELEASE-NOTES-5.1.0b_RC1.html
@@ -139,6 +139,11 @@ spanned display (<code>-tmfds 1</code> and <code>-tmfds 3</code>), not only the
 <p>If your pod drives any MFD or radar panel at all, this applies to you. It is not specific to
 the new split-MFD feature: the underlying Windows limitation affects every mode that lights up
 a second display. On Windows XP none of this was needed.</p>
+<div class="warn"><p><strong>dgVoodoo2 is not part of the build, and must NOT be installed on Windows XP pods.</strong>
+XP uses the graphics support built into Windows and needs nothing extra -- adding dgVoodoo2
+there will break it. It is a per-machine prerequisite that you install yourself, on
+<strong>Windows 10 and 11 pods only</strong>. If your fleet is mixed, set it up per machine, not as part
+of the game folder you copy around.</p></div>
 <p>In the dgVoodoo2 control panel, on the <strong>General</strong> tab, set:</p>
 <div class="note"><p><strong>Scaling mode: <code>Stretched, Keep Aspect Ratio</code></strong></p></div>
 <p>This is not optional and not cosmetic.</p>
diff --git a/RELEASE-NOTES-5.1.0b_RC1.md b/RELEASE-NOTES-5.1.0b_RC1.md
index 252a3d65..95644b4d 100644
--- a/RELEASE-NOTES-5.1.0b_RC1.md
+++ b/RELEASE-NOTES-5.1.0b_RC1.md
@@ -146,6 +146,12 @@ If your pod drives any MFD or radar panel at all, this applies to you. It is not
 the new split-MFD feature: the underlying Windows limitation affects every mode that lights up
 a second display. On Windows XP none of this was needed.
 
+> **dgVoodoo2 is not part of the build, and must NOT be installed on Windows XP pods.**
+> XP uses the graphics support built into Windows and needs nothing extra -- adding dgVoodoo2
+> there will break it. It is a per-machine prerequisite that you install yourself, on
+> **Windows 10 and 11 pods only**. If your fleet is mixed, set it up per machine, not as part
+> of the game folder you copy around.
+
 In the dgVoodoo2 control panel, on the **General** tab, set:
 
 > **Scaling mode: `Stretched, Keep Aspect Ratio`**