Right-click on part01.rar and select using WinRAR or 7-Zip . It will automatically pull data from all other parts (including part 09).

Open the extracted folder and run setup_medieval_dynasty_xxxx.exe . Follow the GOG installer prompts. Play the game directly from the desktop shortcut.

If the extraction stops and asks for Part 09, ensure the file is named exactly Medieval Dynasty GOG.part09.rar and is in the same directory as the others.

If you get an error specifically for Part 09 during extraction, it means that specific file is corrupted. You must delete part09.rar and re-download it.