HOWTO: Multibox Guild Wars 2 on one PC
1. Minimum ISBoxer version
Be on the latest ISBoxer, currently that is 40.3.825.1 (Help->About ISBoxer)
2. Minimum Inner Space version
Be on the latest Inner Space development build, currently that is build 5668 (right click IS, select Patcher, check "Download development (test) patches" then close and restart Inner Space to let it patch up).
3. Make additional folders
You'll want a copy of the Guild Wars 2 folder for each instance of the game you want to run. You are expected to know how to do this step on your own for the purposes of this guide; sorry. Nothing special about the copies, just get yourself multiple Guild Wars 2 folders.
4. Add Game to Inner Space
Use "Add Game" from the Inner Space menu for each folder you created in step 3. This will set up a "Game" and "Game Profile" for use in the Quick Setup Wizard (step #5).
5. Run the Quick Setup Wizard
Run the wizard... Select Guild Wars 2 from the first drop-down box (instead of "Other") and it will set up GW2-specific options as needed.
The wizard only lets you pick one Game and Game Profile, even though you configured multiple Games and Game Profiles in step #4. That's okay. Just pick the first one. We're going to change them in Step #6 below.
6. Configure the Game and Game Profile per Character
In the top left pane, under Characters, select each Character. Then in the bottom right pane, there are drop-down boxes for Game and Game Profile. Point each Character that will be online at the same time to a different Game and Game Profile.
7. Done
All standard from there, see the Quick Start Guides if needed.