I just signed up for a second account and decided to give multiboxing a try today.
I read a lot of articles on how to set it up. Originally I tried running 2 instances from the same wow install folder (on C: drive) but the new account/character wouldn't load. I finally narrowed it down to some add-ons causing conflict (haven''t narrow down to which on yet).

In some of the articles I read it said that running wow from 2 folders on 2 separate drives improves performance, so I decided to do that. Aloso the plan was to limit the addons for the 2nd account (so the game would actually load). and since I have 2 monitors, so I want to use different video settings for the second account (so it can run on the second monitor)

So, I copied the warcraft folders from c: onto my g: drive (which is also a different physical disk).
I did not copy the /interface or /wtf folders.
However, when I ran wow from the g: drive, it loaded all the addons from the c: drive.
???
I read this post: http://eu.battle.net/wow/en/forum/topic/5208453977 with a suggestion on how to 'fix' this issue - I followed the steps and when I ran from the g: drive, it didn't load any addons.

Then I went back and tried to run wow from the c: drive, now it finds no addons, so guessing it is running from the g: folder now.

How can I get it when I run the launcher from the c: drive to load all the settings/addons from the c: drive, and then the same for the g: drive?
Many of the articles I read suggested running from 2 wow folders, but I can't seem to figure out how to get that to work? Is it still possible?