How to Tie a Tie: Half-Windsor Knot - A kid teaches other kids how to tie a tie using the simple half Windsor knot,Everyone should know how to tie a tie. The half-windsor knot is one of the simplest knots and can serve children well until they learn fancier knots. So, whether your child wants to learn to tie her new Harry Potter tie or needs to learn to tie a tie for an award acceptance ceremony, here’s a brief how-to video on how to tie a Half-Windsor knot with step-by-step instructions.