If you are installing this ISO, you must keep three critical things in mind:

A dedicated machine for Windows 95/98/XP era games (Half-Life 2, Diablo II, Age of Empires II) that struggle to run on Windows 10/11.

SP3 included the "Wireless Provisioning Services" element. This allowed for easier connection to "Wi-Fi hotspots"—a burgeoning technology in 2008. It improved the "Connect to a network" wizard, making it far more reliable than the clunky SP2 implementation.