FUEL lacks the ability to launch in windowed mode via the provided launcher or in-game settings, but here is a short guide to manually set this via two simple file renames and a launch option from within the Steam Client.

The first thing you need to do is navigate to your FUEL directory. This can be done easily via the Steam Client:

• Right click on your FUEL game entry within your game library.
  
• Click "Properties".
  
• Navigate to the "Local Files" tab and then click on the "Browse Local Files" button as shown in the image below.

Next you need to rename the following files in the base FUEL directory:

• "GameSetup.exe" to "GameSetupBACKUP.exe"
  
• "SecuLauncher.exe" to "GameSetup.exe"

What this is essentially doing is when you launch FUEL via the Steam Client it will now bypass that initial game launcher. This allows us to set launch options directly to the game itself, rather than the launcher. At any time you can simply rename those files back to how they were to get that launcher back, but you will not be able to launch the game in windowed mode via Steam.

The next step is to set the launch option. This can be done easily via the Steam Client:

• Right click on your FUEL game entry within your game library.
  
• Click "Properties".
  
• Click on the "Set Launch Options" Button and enter "-W" in text field as shown in the image below.

Now when you launch the game it will run in windowed mode. To run in full-screen mode again, simply remove the "-W" launch option you entered earlier.