The software is vulnerable to modern exploits.
Background
If you choose to use it for nostalgic or lightweight productivity reasons, here is the consensus from reviewers at CNET and MouthShut : : microsoft office 2003 72 mb download
If you are running Windows 10 or 11, Office 2003 may struggle to function correctly. The software is vulnerable to modern exploits
A standard installation of Microsoft Office 2003 Professional typically requires between 380 MB and 450 MB go to Properties
Right-click the setup file, go to Properties, and set it to run in Compatibility Mode for Windows XP (Service Pack 3).
Even after extreme stripping, such builds are —still double 72 MB. So a 72 MB file would likely be missing critical system components.