Hello Marie_FMI!

There's an option in QuickBooks Desktop to automatically build subassemblies. This is the reason why you're seeing auto-created assemblies. Allow me to help you in turning it off.

Please follow these steps:

1. Go to the Lists menu and select Item List.
2. From the Activities drop-down, select Build Assemblies.
3. Select an assembly item on the Assembly Item drop-down.
4. Uncheck the Automatically build required subassemblies box.
5. Tap Build & Close.

I've added some links you can check. These will explain more on how to manage your items in QuickBooks Desktop:

• Add, edit, and delete items

• Combine your inventory items to build finished goods

I'm only a post away if you have additional questions. Take care always!