If you own a physical copy, use that. If downloading, use reputable retro-gaming archives (like the Internet Archive or well-moderated retro preservation sites) rather than random "Free Download" portals.
: For detailed deck-building strategies to defeat Kaiba's specific tactics (like his "stealing" deck), refer to community guides on tool, or do you need help fixing a "Cannot find CD-ROM" error during setup? Yu-Gi-Oh! Power of Chaos: Kaiba the Revenge - GameFAQs Setup Exe Yugioh Kaiba The Revenge