The 500 MB file is not the actual software, but a downloader program that will attempt to fetch the remaining gigabytes of data from an unofficial third-party server during installation.
You can check if your existing installation is genuine by going to File > Account and looking for the "Product Activated" status. Minimum System Requirements
If your primary goal is Office 2019 itself, Microsoft remains the only legitimate source. microsoft office 2019 highly compressed 500mb extra quality
Which could lock your files until you pay a fee. 2. Stability Issues
A standard installation of Microsoft Office 2019 contains massive amounts of data, including advanced code libraries, font packages, localized language files, and templates for applications like Word, Excel, PowerPoint, and Outlook. The 500 MB file is not the actual
0 MB (runs entirely inside your web browser).
While the idea of a installer is appealing, it is important to understand what these versions actually are and the risks involved in downloading them. What is a "Highly Compressed" Version? Which could lock your files until you pay a fee
: If it’s significantly smaller than the official Microsoft ISO, it's fake.