You will need to download RPG Maker, the RTP, and the game, right click all of the executables, and under "Compatibility," either set it to run under compatibility mode for "Older Versions of Windows" or "Vista Service Pack 2". You will also need to set your system locale to Japan, because applocale fails to work when trying to run RPG_RTP.exe through it on Windows 8. I did all of this, and I was just playing De i Cide yesterday. Hope that helps :)