If you absolutely need the exact Minitab 17 interface and cannot adapt, consider a short-term rental: Some cloud-based platforms offer Minitab on-demand for ~$10/hour.
If you previously purchased Minitab 17 and lost your 18-digit key, you may be able to recover it by contacting Minitab Technical Support or by checking your original order confirmation email. UNSW Sydney Activation Process (18-Digit Format)