There are several alternatives to KMS activator for activating Windows or Office legally. One of the most common methods is to purchase a valid product key from Microsoft or an authorized retailer. For Windows users, the built-in activation feature allows you to enter your purchased key directly through the Settings menu. Another option is to use the Microsoft Software Assurance program, which provides volume licensing solutions for organizations. Additionally, Microsoft offers free trials for some products, allowing users to test software before committing to a purchase.