if you're having problems with the interview and don't plan to claim the child, for ANY tax benefits, just delete the dependent. The interview is complicated to accommodate the special rules for divorced and separated parents. If you live with the other parent, definitely delete the child. The special rules do NOT apply to parents living together.
If the child lived with you, as a separated parent, for more than half the year, you can still claim Head of Household, Dependent Care Credit, and EIC, even though the other parent is claiming the dependent and child tax credit. But to do so, you need to answer that he lived with you for 7 months or more. The interview will ask if you are letting the other parent claim him as a dependent.
