Question: How to change the default icon of my Processing `appIconTest.exe` exported 
application in windows ? 

**The default one :**

[![app icon to change](https://i.stack.imgur.com/u114Y.png)](https://i.stack.imgur.com/u114Y.png)

Answer: 
After some research, the easiest solution i could find is :

1. Go into `...\processing-3.0.1-windows64\processing-3.0.1\modes\java\application`
2. Save `sketch.ico` somewhere you can find (renaming it will help).
3. Place the icon you want to use in the same folder with the same name `sketch.ico` (which you might create using [GIMP](https://www.gimp.org/)).
4. Now you can export your application from Processing.

---

**Important :** Be sure to save the default icon, because every application you export (after changing the icon) using Processing, will have this new icon.
I would recommend Resource Hacker to change the icon of your programs.

1. Install Resource Hacker (latest build).
2. Go to your executable file.
3. Open it with Resource Hacker (right mouseclick, and there should be an option to do that or else you could just click open with).
4. It will open and show some directories, also one called "Icon", open that one, and right click one one of the icon files (stars with some numbers after that), there will be an option: "replace icon ... Ctrl + R", click that one and replace your icon.