To do what you want. You have a little work to do. 1. Seperate them to different folders. (I think you do already) Like USA, Euro, Japan, nodumps, etc. Easiest to use a no-intro set to start with. 2. Get a file renamer, remove all the extentions from the file names in all the folders. Your roms should just be the game name. 3. Then drop the euro files into the japan folder. Then the USA files in he Japan folder overwriting all files all the time. That will make the euro (english) files replace any of the same games that are in Japanese. Then when you dump the USA roms in the japanese folder, they will over write any of the same games leaving you with 1 of each game. Mostly USA, and some euro or japanese if there is not a USA version. 4. Run the new set back through romcenter and have it put the correct names (with extensions) back on if you want. You have to decide how you want them to be. Think about how they will match with snaps and etc. You should decide if you want to keep them in a zip file before you start or just the rom. If you keep them in a zip file, the actual rom names will never be changed. Only the zip file name. Its up to you. Ill see if I can make some useable dats for romcenter with the emulators I use. I have done that work to all my emulators.