step1 :Use Attach window activity and inside the container click on the"Indicate window on screen" and here select your IE/Chrome whole window, which has the output variable as windows type ,give some variable name (X) in the property section.
step2: inside the “do” container use the “Maximize activity” and pass the window variable(X) as the input.
step 3: As browser is dynamic you need to modify the selector by clicking on “attach the live element” from selector editor and click on the browser window.
hope this works for you.