Regarding emunand, it is on a hidden partition on the SD card so deleting it has to be a bit more involved. Even formatting from windows would not get rid of emunand as windows format utility can't see it. I beleive SD Formatter removes it but I have not personally test that so I am not sure.deleting the launcher.dat file does not remove emunand. You have to manually delete that as well. Thats I use separate SD cards just for this type of thing that you're trying to do.