The safest way to get a smaller installation is to seek out a "lite" version from a well-known and trusted developer in the software community. One popular example is the xb21cn Office 2016 build. It's known for being a trimmed-down version, often retaining the core components while removing unnecessary extras. It can be a good option for users with basic needs, though it may have compatibility issues with some advanced features or complex documents.
Includes essentials like Word, Excel, PowerPoint, and Outlook. Key Features of the 100MB Version
This does not require installation. You run it from a USB drive, and it is usually pre-activated.
Check if your school email address qualifies you for a free Office 365 Education account.
A legitimate Microsoft Office 2016 Professional Plus installation typically requires 3GB to 4GB of free hard disk space. The "100MB" Claim:
Often, these downloads come with cracked activation tools that are known vectors for ransomware. Best Alternatives for Low-Resource Scenarios
the MS_Office_2016_Compressed.7z (or similar extension) file.
Open your web browser and navigate to Office.com.
If you still want a third-party solution, xb21cn is a well-known creator of "green" Office versions in the Chinese software community. Their 2016 version is around 150-200MB, not 100MB. While respected by some, you are still installing software from an unofficial source.
No internet connection is required during the actual setup process once downloaded.