Microsoft offers completely free, browser-based versions of Word, Excel, PowerPoint, and OneNote. You just need a free Microsoft account (Outlook.com, Hotmail, etc.). They lack advanced features like macros and pivot tables, but for 90% of home users, they are sufficient.
If verified, the system generates a 48-digit Confirmation ID (divided into groups A through H), which you enter into the Activation Wizard to unlock the software. Warning: Third-Party "Generators" microsoft office confirmation id generator