Set a custom background image in Windows File Explorer — with live preview, brightness, blur, opacity controls, foreground overlays, desktop wallpaper sync, and auto-start on boot.
Built with Python + a browser-based UI. Works on Windows 10 and Windows 11.
⚠️ This tool uses a DLL hook to inject a background into Explorer. It works great but Microsoft occasionally patches these hooks in major Windows Updates — if your background disappears after an update, just click Apply again in the app.
┌─────────────────────────────────────────────────────────┐
│ > This PC 🔍 Search This PC │
├─────────────────┬───────────────────────────────────────┤
│ 🏠 Home │ │
│ 🖼️ Gallery │ [ Your beautiful image fills here ] │
│ │ 🎨 │
│ 📁 Desktop │ 🌸 anime / artwork / photo │
│ 📁 Documents │ [logos!] │
│ 📁 Downloads │ │
└─────────────────┴───────────────────────────────────────┘
| Requirement | How to get it |
|---|---|
| Windows 10 or 11 | You already have it 😄 |
| Python 3.8+ | python.org/downloads |
| Pillow | Auto-installed by start.bat |
🔴 Critical during Python install: Check "Add Python to PATH"
☑ Add Python to PATH ← tick this, it's unchecked by default!or one can simply use below command example in cmd admin mode to install any Python version 3.8+ (this Auto-Adds Python to PATH)
winget install -e --id Python.Python.3.13
Right after cloning:
ExplorerBgTool/
│
├── 📄 explorer_bg_tool.py ← The main app (Python)
├── 📄 wallpaper_watcher.py ← Standalone wallpaper sync watcher
├── 📄 ExplorerBgTool.dll ← The DLL that hooks into Explorer
│
├── 🖱️ start.bat ← START HERE — launches the control panel
├── 🖱️ SETUP_AUTOSTART.bat ← Run once to survive reboots
├── 📄 setup_autostart.ps1 ← Called by SETUP_AUTOSTART.bat (don't delete)
├── 🖱️ REMOVE_AUTOSTART.bat ← Removes auto-start if you want to undo
│
└── 📄 README.md ← You are here!
After running the app for the first time, these appear automatically:
ExplorerBgTool/
│
├── 📄 bg_config.json ← Your saved settings (auto-created)
├── 📄 config.ini ← explorerTool config (auto-created on Apply)
├── 📄 launch_bg_silent.vbs ← Silent boot launcher (auto-created by SETUP_AUTOSTART)
│
├── 📁 image/
│ └── 🖼️ bg_custom.png ← Your processed & composited background (auto-created)
│
└── 📁 .wallpaper_cache/
├── 🖼️ current_wallpaper.jpg ← Desktop wallpaper copy (if wallpaper mode used)
└── 📄 watcher.log ← Wallpaper watcher activity log
git clone https://github.com/SuryaMajumder/ExplorerBgTool.gitOr click Code → Download ZIP on GitHub and extract it anywhere (Desktop, C drive, wherever).
Double-click start.bat
start.bat
└─→ asks for admin privileges → click Yes
└─→ auto-installs Pillow if missing
└─→ opens your browser at http://127.0.0.1:57821
💡 The CMD window that opens must stay open in the background — it's the server powering the browser UI. Don't close it while using the app.
The browser control panel looks like this:
┌──────────────────────────────────────────────────────────────────────────┐
│ 🖼️ Explorer Background Tool ✓ Administrator │
├───────────────────────────────────────┬──────────────────────────────────┤
│ │ BACKGROUND POSITION │
│ [ Live Preview — all layers ] │ ↖ TL ↑ Top ↗ TR │
│ │ ← Left ⊙ Ctr → Right │
│ Background + overlays composited │ ↙ BL ↓ Bot ↘ BR │
│ in real time! │ ⊞ Zoom & Fill ← recommended! │
│ ├──────────────────────────────────┤
├───────────────────────────────────────┤ EXPLORERTOOL DLL │
│ 🌄 BACKGROUND LAYER │ [ ExplorerBgTool.dll ] [Browse] │
│ [ image.jpg ] [Browse][🖥️ Wallpaper] ├──────────────────────────────────┤
│ [🗑 Clear] │ ACTIONS │
│ ✨ Brightness ───●───── 1.0× │ ✅ Apply to Explorer │
│ 🎨 Contrast ───●───── 1.0× │ 🔄 Restart Explorer │
│ 🌫️ Blur/Haze ●───────── 0px │ ❌ Uninstall Background │
│ 💧 Opacity ──────●── 255 │ │
├───────────────────────────────────────┴──────────────────────────────────┤
│ 🎨 FOREGROUND OVERLAYS (optional — add as many as you want) │
│ ┌─────────────────────────────────────────────────────────────────────┐ │
│ │ 🎨 Overlay 1 [ chibi.png ] [Browse] [✕] │ │
│ │ Position: ↖TL ↑Top ↗TR ←Left ⊙Ctr →Right ↙BL ↓Bot ↘BR │ │
│ │ 📐 Size ──●────── 30% ✨ Brightness ──●── 1.0× │ │
│ │ 🌫️ Blur ●──────── 0px 💧 Opacity ──────●── 255 │ │
│ └─────────────────────────────────────────────────────────────────────┘ │
│ [ + Add Foreground Image ] │
└──────────────────────────────────────────────────────────────────────────┘
Click Browse under the 🌄 BACKGROUND LAYER section and select any image file:
| Supported formats |
|---|
.png .jpg .jpeg .webp .bmp |
The Live Preview box updates instantly — what you see there is exactly what Explorer will show.
You have three options for the background:
| Button | What it does |
|---|---|
| Browse | Pick any image from your PC |
| 🖥️ Wallpaper | Use your current desktop wallpaper (auto-syncs if Spotlight!) |
| 🗑 Clear | Remove the background image (overlays remain untouched) |
| ☑ Also apply to Windows file picker dialogs | When checked, your background + overlays also appear in Save As / Open File dialogs system-wide |
| Slider | What it does | Sweet spot |
|---|---|---|
| ✨ Brightness | Makes the image lighter or darker | 0.4–0.7× — dim it so folder icons stay readable |
| 🎨 Contrast | Increases or decreases image contrast | 0.8–1.3× — subtle boost makes colors pop |
| 🌫️ Blur / Haze | Adds a frosted-glass dreamy haze | 3–8px for a subtle glow effect |
| 💧 Opacity | How see-through the image is | 80–180 balances beauty and readability |
💡 Watch the Live Preview as you drag — it updates after you release the slider. (P.S.: Dark Mode of Windows gives better vibe with darker backgrounds than Light mode and vice-versa.)
| Option | What it does | When to use it |
|---|---|---|
| ↖ Top Left | Anchors to top-left, no scaling | Fixed decorative corner image |
| ↗ Top Right | Anchors to top-right, no scaling | Fixed decorative corner image |
| ↙ Bot Left | Anchors to bottom-left, no scaling | Fixed decorative corner image |
| ↘ Bot Right | Anchors to bottom-right, no scaling | Fixed decorative corner image |
| ⊙ Center | Centers the image, no scaling | Small icons or logos |
| ⤢ Stretch | Stretches to fill the window | May distort the image |
| ⊞ Zoom & Fill | Scales to always fill — no cutoff | Use this! Best for photos & artwork |
✅ Recommendation: always use Zoom & Fill. It makes the image resize perfectly with your Explorer window no matter how you drag or snap it. Unless using anime figures which stays at fixed positions.
This is where it gets fun! You can pin any number of images on top of your background — like anime chibis, stickers, logos, or artwork — each independently positioned and styled.
Click + Add Foreground Image at the bottom of the page. Each overlay gets its own card:
┌────────────────────────────────────────────────────────┐
│ 🎨 Overlay 1 [ chibi.png ] [Browse] [✕ Remove] │
│ │
│ POSITION (pick where it's pinned) │
│ ↖ TL ↑ Top ↗ TR │
│ ← Left ⊙ Ctr → Right │
│ ↙ BL ↓ Bot ↘ BR ← (default) │
│ │
│ 📐 Size ──●────── 30% (% of screen height) │
│ ✨ Brightness ──●────── 1.0× │
│ 🌫️ Blur ●──────── 0px │
│ 💧 Opacity ────────── 255 │
│ │
│ ▸ ADVANCED (click to expand) │
│ ↔️ Left→Right ──────●── 100% (custom X position) │
│ ↕️ Top→Bottom ──────●── 100% (custom Y position) │
│ 🎨 Contrast ───●────── 1.0× │
│ [↔ Flip H] [↕ Flip V] │
│ 🔄 Rotation ───●────── 0° │
└────────────────────────────────────────────────────────┘
What each overlay control does:
| Control | What it does | Tips |
|---|---|---|
| Browse | Pick the overlay image | PNG with transparent background works best! |
| ✕ Remove | Delete this overlay | Preview updates instantly |
| Position grid (3×3) | Pin the overlay to any of 9 positions | TL/TR/BL/BR for corners, Top/Bot/Left/Right for edges, Center for middle |
| 📐 Size | Scale the overlay (5%–80% of screen height) | 20–35% looks natural for character art |
| ✨ Brightness | Brighten or dim the overlay independently | Keep at 1.0× for crisp artwork |
| 🌫️ Blur | Blur the overlay | 0 for sharp, 2–5 for dreamy/ghosted effect |
| 💧 Opacity | How transparent the overlay is | 180–255 for solid, lower for ghosted |
| ▸ ADVANCED | Expand for fine-tuning controls | Click to toggle open/closed |
| Custom X position (0%=left edge, 100%=right edge) | Overrides the 9-position grid for pixel-perfect placement | |
| Custom Y position (0%=top, 100%=bottom) | Use with Left→Right for full free positioning | |
| 🎨 Contrast | Increase or decrease overlay contrast independently | 1.0× = no change |
| ↔ Flip H | Mirror the overlay horizontally | Toggle — highlighted when active |
| ↕ Flip V | Mirror the overlay vertically | Toggle — highlighted when active |
| 🔄 Rotation | Rotate the overlay 0°–359° | Applied after flipping |
💡 Pro tip: Use a PNG with a transparent background for your overlays (like chibi character art) — the transparency is fully preserved so only the character appears, with no white/solid box around it!
💡 Overlay position is fixed — unlike the background which can Zoom & Fill, overlays are always pinned to their chosen corner/edge regardless of how you resize the Explorer window. This is intentional — it keeps your chibi army exactly where you want them!
💡 Custom positioning — the 9 position buttons are shortcuts. For pixel-perfect placement, open ▸ ADVANCED and use the Left→Right / Top→Bottom sliders. Dragging these deactivates the 9 buttons (custom mode). Clicking any position button snaps the sliders back to that anchor and re-activates it.
💡 No background needed — you can use overlays without any background image! In that case, Explorer's own theme color (light/dark) shows through naturally.
You can add as many overlays as you want. They all composite into one final image before being sent to Explorer.
Under EXPLORERTOOL DLL, click Browse and select ExplorerBgTool.dll from your folder.
You only need to do this once. The path is saved in
bg_config.jsonautomatically.
- Click ✅ Apply to Explorer
- A green message appears: "Applied! Now restart Explorer."
- Click 🔄 Restart Explorer
- This briefly closes and reopens Explorer (all windows will flash — that's normal)
Open File Explorer and enjoy your background! 🎉
💡 Note background doesn't appear at Home and Gallery of File Explorer. You can browse to any other location and your background will appear.
💡 Want your background in Windows file picker dialogs too (Save As, Open File, etc.)? Tick ☑ Also apply to Windows file picker dialogs before clicking Apply!
Instead of picking a custom image, you can use your current desktop wallpaper as the Explorer background — and keep it in sync automatically!
Click 🖥️ Wallpaper in the Background Layer section. The app will:
- Copy your current desktop wallpaper (works with both custom wallpapers and Windows Spotlight)
- Apply it as your Explorer background
- Show a green ⟳ auto-sync badge
🌄 BACKGROUND LAYER
[ current_wallpaper.jpg ] [Browse] [🖥️ Wallpaper] [🗑 Clear] ⟳ auto-sync
When auto-sync is on, the app checks every 30 minutes for wallpaper changes. If your Spotlight wallpaper rotated, it automatically re-applies the new one to Explorer — silently, no popups.
To turn off auto-sync: just click Browse and pick a custom image. The badge disappears and the watcher stops.
| Wallpaper type | Button works? | Auto-sync works? |
|---|---|---|
| Custom image (static) | ✅ | ✅ stays fixed, watcher idles |
| Windows Spotlight | ✅ | ✅ updates when Spotlight rotates |
| Solid color desktop | ❌ no image to grab | — |
By default the background resets when you restart Windows. Run this once to fix that:
Prerequisites: Complete Steps 2–8 above first so bg_config.json exists.
- Double-click
SETUP_AUTOSTART.bat - Click Yes on the admin prompt
- A green message confirms everything is registered
To verify it worked:
- Press
Win + R→ typetaskschd.msc→ hit Enter - Look for both tasks in the Task Scheduler list:
Task Scheduler Library
├── ✅ ExplorerBgTool ← applies background on every login (always runs)
└── ✅ ExplorerBgWatcher ← wallpaper auto-sync watcher (exits if not in wallpaper mode)
From now on your background applies silently every time you log into Windows — no CMD window, no browser, just instant background. Exactly like a wallpaper.
What each task does on login:
| Task | What it does | When it runs |
|---|---|---|
| ExplorerBgTool | Registers the DLL — instantly applies last saved background | Always, every login |
| ExplorerBgWatcher | Checks if wallpaper changed, re-applies if yes | Only when wallpaper mode is ON, exits immediately otherwise |
Just run start.bat anytime:
start.bat → Browse new image → adjust sliders → ✅ Apply → 🔄 Restart Explorer
Settings save automatically. No need to run SETUP_AUTOSTART again.
start.bat → ❌ Uninstall Background → 🔄 Restart Explorer
1. start.bat → ❌ Uninstall Background → 🔄 Restart Explorer
2. Double-click REMOVE_AUTOSTART.bat → click Yes
If Explorer keeps crashing after a Windows Update broke the hook:
1. Hold ESC and click Explorer in the taskbar
└─→ This opens Explorer WITHOUT loading the background
2. Run start.bat → ❌ Uninstall Background
3. 🔄 Restart Explorer
| Problem | Fix |
|---|---|
start.bat closes instantly |
Python not installed, or "Add to PATH" wasn't checked during install |
| Browser doesn't open | Manually go to http://127.0.0.1:57821 in your browser |
| Top-right badge says "Not Admin" | Close and re-run start.bat — click Yes on the UAC prompt |
| "regsvr32 failed" error | You're not running as admin — re-run start.bat and click Yes |
| Background disappeared after Windows Update | Run start.bat → Apply → done |
| Explorer crashes on open | Hold ESC while clicking Explorer → then Uninstall from app |
| Image gets cut off at window edges | Switch to Zoom & Fill position in the app |
| Overlay has white/black box around it | Use a PNG with transparent background for overlays |
| 🖥️ Wallpaper button shows error | Solid color desktop has no image to grab — pick an image instead |
| Wallpaper auto-sync not working after reboot | Run SETUP_AUTOSTART.bat again — makes sure watcher task is registered |
| File | Purpose | Safe to delete? |
|---|---|---|
explorer_bg_tool.py |
Main Python app | ❌ No |
wallpaper_watcher.py |
Standalone wallpaper sync watcher | ❌ No |
ExplorerBgTool.dll |
Explorer hook DLL | ❌ No |
start.bat |
Launches control panel | ❌ No |
SETUP_AUTOSTART.bat |
Sets up boot auto-start | ✅ After running once |
setup_autostart.ps1 |
Called by SETUP_AUTOSTART | ❌ Keep alongside the BAT |
REMOVE_AUTOSTART.bat |
Removes boot auto-start | ✅ Optional to keep |
bg_config.json |
Saved settings | ❌ No (holds your DLL path etc.) |
config.ini |
explorerTool config | ❌ No (re-created on Apply) |
launch_bg_silent.vbs |
Silent boot launcher | ❌ No (needed for auto-start) |
image/bg_custom.png |
Processed & composited background | ❌ No (re-created on Apply) |
.wallpaper_cache/ |
Desktop wallpaper cache folder | ✅ Safe, auto-recreated |
- Combine low brightness + slight blur for a gorgeous frosted glass look
- The app processes your image before applying — your original file is never modified
- You can keep multiple images and swap them anytime via the app
- GIF and live wallpapers are not supported inside Explorer (Windows limitation)
- If you move the folder to a new location, just run
start.bat, click Browse DLL to repoint to the DLL, Apply, then runSETUP_AUTOSTART.batagain - Overlays are composited at 4K resolution before being sent to Explorer — they stay sharp even on large monitors
- Overlay position is absolute — the chibi stays in its corner even when you resize Explorer. Background uses Zoom & Fill so it always scales. They work independently!
- Check
.wallpaper_cache/watcher.logif wallpaper auto-sync isn't behaving as expected — it logs every check and apply
- Maplespe — for the original
ExplorerBgTool.dllthat makes all of this possible - Python GUI, browser UI, foreground overlay system, wallpaper sync, and tooling built on top of it
MIT — do whatever you want with the Python and BAT code.
The ExplorerBgTool.dll belongs to Maplespe under their original license.