I'm trying to find a way into playing the game but they don't seem to want to open the the file. Is it unavailable to play nowadays?
What is the error you are receiving? If it's something about a System file, you can try downloading the RPG Maker 2003 RTP here (Scroll down, select 'RPG Maker 2003', then press 'Download Run Time Package'). Let me know if that fixes the issue.