Step 1: Open Qt Creator and Go to Options

1. Open Qt Creator.

2. In the top menu, go to Tools > Options (on Windows/Linux) or Qt Creator > Preferences (on macOS).

Step 2: Modify the Kits Configuration

1. In the Options/Preferences window, go to the Kits tab under the Build & Run section.

2. You'll see a list of all available kits. These kits represent different Qt versions, compilers, and platforms.

3. To prevent Qt Creator from enabling all kits by default:

   • Uncheck the kits you don't want to use by default.

   • Leave checked only the ones you wish to work with.

Step 3: Choose Specific Kits for Your Project

When you create a new project:

1. After selecting the project template and proceeding with the setup, you’ll be asked to choose a kit.

2. Here, you can manually select the kit(s) you want to use for that project. It will show only the kits that are checked in the Kits tab.

Step 4: Save Changes

After unchecking the unnecessary kits and selecting your desired kit(s) for a new project, click OK or Apply to save the settings.

Additional Tips:

• If you want to use multiple kits but not all, you can configure specific kits for different platforms (e.g., one for desktop, one for mobile).

• You can also edit project files later to switch kits if needed.