You can delete a project by right-clicking its folder in the SQL Project Explorer and selecting Delete.

When you delete a project, DB Optimizer will prompt you with a Confirm Project Delete dialog that asks you to confirm the deletion of the project, and offers you the option of deleting the project from the DB Optimizer interface, or deleting the project from the system.

• If you select Do not delete contents, the files and directory structure will be removed from SQL Project Explorer, but they will still exist on your machine.
• If you select Also delete contents …, the files and directory structure will be removed from SQL Project Explorer and deleted from your machine.