If you want to clear/reset all of your data - that means all of your sending history will be removed, all of your gathered users will be deleted, everything will be gone from Tube Toolbox, you can follow the instructions below.
All of your Data is in a single file. If you delete that file, you will remove all of your data.
To find the file, launch Tube Toolbox and click on the Folder icon on the log-in screen.
Once the folder on your computer shows up, CLOSE TUBE TOOLBOX.
Delete the file in the folder that is called: TubeToolboxData.sdf
Re-open Tube Toolbox and you will have a fresh new start