Hello!

I have just discovered the joy of roms and whatnot, and I recently saw that you have my all-time favorite game, Pokemon XD Gale of Darkness. I had this game as a child and played it into the ground! Now that I'm in college, I don't have my Gamecube or games, and I am trying to get it onto my computer.
I downloaded the .7z file of the game, and the recommended emulator: Dolphin, for the game to run, but when I open Dolphin, it says I have no games for it, then when I tried to extract it I get a Disc Image File from it, and nothing happens, it says it is "corrupt" and Dolphin still doesn't recognize it. When I go in, I can get all the way to it, but I can't click on it.... any suggestions?!