Unlocking all cards in the Yu-Gi-Oh! Power of Chaos trilogy involves replacing the system.dat file in the shared "Common" folder and applying a registry patch. For modern Windows, running the game as an administrator is required, with additional community mods available to unlock expansion sets and Egyptian God cards. Find user-shared files and instructions at Reddit r/yugioh/comments/rjw1sz/completed_card_collection_of_yugioh_power_of/.

: If your game is installed in a non-default directory, you must edit the file with Notepad to match your actual Overwrite System Data : Replace the system.dat

Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\KONAMI\Yu-Gi-Oh! Power of Chaos\system .

Are you trying to to a specific game in the trilogy, or