By correctly setting up the PES 2013 registry for your 32-bit system, you bypass installation errors and can get straight back to the pitch. This method is especially helpful for those using "repack" versions of the game or those trying to keep the classic title alive on older hardware.
Path Accuracy: A single typo in the folder path within the registry will cause the "not installed" error to persist.
Crucial Step: Change the "installdir" path to match where your game is actually saved. Use double backslashes (\) between folders.