Once you have the VM set up and your Java path properly configured (javaw, etc.), run the installer. Success! Your new instance should run in about 2GB of memory. We recommend you run just a single instance of Custom Minecraft to improve stability and load speed. On dual GPU machines, you may have to run a separate instance of Custom Minecraft (which requires two VRAM slots) to get the best performance.
Your saved game files and world data files should be located in your Downloads folder. Even though you can play Custom Minecraft in a Download folder, it is recommended you keep the game in a folder you call minecraft. The reason for this is Custom Minecraft will use the game's original minecraft.jar file (which will typically be found in the main folder). If the minecraft.jar file is moved, you will probably have to change the jar's name back to minecraft.jar in order to load the game properly.
Custom Minecraft can be launched by Minecraft launcher maps or command line arguments. To launch Custom Minecraft from the command line, just pass the program name and launch the launcher like so: d2c66b5586