First make sure your iso is not PAL, you need to rip your brawl iso off of an NTSC disc. Then, follow the steps listed here -> http://smashboards.com/threads/project-m-dolphin-online-via-netplay-full-setup-optimization-guide.346700/ and you can create a brawl iso injected with PM aka no gecko loading. The method in that video sucks unless you're testing texture packs and other custom stuff and whatnot, and btw no DVD error is probably because you have a PAL iso/scrubbed iso.
[color=green]Windows 7 x64 / i5 4690k @ 3.5 GHz / GTX 970 / 8GB RAM[/color]