In this tutorial we will help you render this keyboard shortcut operational using simple instructions. After some few modifications, you will be able to run commands via the Unity Dash or Gnome Shell once pressing ALT+F2.
1. On your desktop, click the power button and select System Settings:
2. Click Keyboard.
3. Select the "Shortcuts" tab, then open the System tab. On the right, click Disabled for "Show the run command prompt" entry, then press the ALT+F2 combination to assign it to this command:
4. Your shortcut must be like this:
5. You have now enabled the ALT+F2 combination and once pressed, the run command prompt will show up in the Unity Dash or Gnome Shell.