Report Offensive Message

By 'tasks', do you mean icons? I don't know about the ribbon itself is customizeable, but you can fully customize the 'Quick Access Toolbar'. That's the little toolbar on the left side of the title bar, next to the application logo. Like the Ribbon, the QAT is 'intelligent', changing with each different type of window an application opens; it's different for an Outlook e-mail than an appointment or task.

Right-click the ribbon and select 'Customize Quick Access Toolbar'.