You are referring to a W-4 that you give to your employer that determines the amount of federal income taxes to be withheld from your wages. What is entered on a W-4 is not relevant to what you enter on a tax return.
What are you asking about? Are you asking about the W-4 you give to your employer?
Or are you asking about saying on your tax return that you can be claimed as someone else's dependent? That question appears in My Info so if you have not e-filed you can click edit by your name and change the way you answered that question.