I think the box you have lost may be the tool options. Has options for most - not all tools when they are selected. You must have the tool options box open if thats what you want. If you have inadvertantly closed it follow the followingÂ
Then to make sure you dont lose it and you will also find in that menu where it says 'lock tab to dock' Check it!
Go to edit, preferences and windows management and follow this image
Then to make sure you dont lose it and you will also find in that menu where it says 'lock tab to dock' Check it!
Go to edit, preferences and windows management and follow this image