Why? Because it runs a suite of background services to maintain the visual effects (shadows, transparency) and often includes pre-installed software running in the background. While the ISO claims to be "optimized," the visual flair comes at a cost. It runs smoothly on Core 2 Duo or early i3/i5 processors, but it will struggle on

: It was known for having a massive library of drivers pre-integrated (up to 2008 standards), reducing the need for manual driver installation after setup. Custom Interface

: As an "Integrated ISO," it often includes pre-installed essential software and SATA/RAID drivers that were notoriously difficult to install on standard XP discs. The "2021 Updated" Context