Go to fchartsoftware.com (do not trust third-party mirrors). Navigate to the tab and select "Download."

Downloading EES Engineering Equation Solver Professional is a straightforward process that can be completed in a few simple steps. Here's a step-by-step guide to get you started:

EES Engineering Equation Solver Professional is a comprehensive software package developed to help engineers, researchers, and students solve a wide range of equations, from simple algebraic expressions to complex systems of nonlinear equations. The software is designed to provide an intuitive and user-friendly interface for solving equations, making it an essential tool for anyone working with mathematical modeling, simulation, and analysis.

Even "working" cracks often disable the and prevent Excel automation via DDE (Dynamic Data Exchange). So you end up with a broken professional interface, not real professional power.