Here is what those tutorials will not tell you:
If you have already installed Office Mondo 2016 using a cracked product key and want to clean your system, follow these steps: product key microsoft office mondo 2016
A product key is a 25-character code that is required to activate Microsoft Office 2016. It is used to verify that the software has been purchased and to prevent unauthorized use. The product key is usually provided with the purchase of the software or can be found on the packaging or in the confirmation email. Here is what those tutorials will not tell
If you need Microsoft Office but do not want to pay $150–$400, you have better, safer options. If you need Microsoft Office but do not
Using a volume license key intended for internal Microsoft use falls under software piracy. While Microsoft rarely sues individual home users, your copy of Office will be flagged as non-genuine. You will lose access to security updates, feature updates, and technical support.
The term "Mondo" in the context of Microsoft Office 2016 refers to a particular configuration or suite of Office applications. This can vary but generally includes core applications like Word, Excel, PowerPoint, and Outlook, among others. The Mondo version is often used in volume licensing scenarios, where multiple users within an organization require access to Office.
Microsoft’s activation servers are not stupid. When a single product key is used millions of times across the globe, the company’s anti-piracy systems (including the Volume Activation Services) will detect the abuse. The result? The product key gets revoked. When that happens, you will see a "Product Activation Failed" notice, and eventually, your Office will enter Reduced Functionality Mode (you can only view documents, not edit or create new ones).