Lol, you aren't going to be able to run this emulator at all not even at it's slowest. Hell your PC can't even handle PC games newer than the year 2003/2004/2005..
I would stick to playing on your Wii or Gamcube with your games unless you are willing to fork money over for an expensive upgrade that will run about $600 - $800 to play games on Dolphin halfway decently. In the end the actual Gamecube/Wii + games will be a much cheaper solution.
I'm sorry but that's the sad reality of it, your PC is too ancient to consider running anything else other than really old PC games that don't use shaders or Hardware T & L. Don't expect to be able to use CPU/GPU intensive emulators like Pcsx2 or Dolphin that require a fairly strong dual core cpu and a graphics card that supports Pixel/Vertex shading 2.0 or better.
