Originally Posted by
Lolaids
Here is how to have 2 or more instances of WoW open. The instances can be of different realmlists (ie, retail+a private server, 2 or more different private servers)
1. Go to your WoW folder and open up WoW.exe
2. Minimize WoW and go back to your WoW folder.
3. Open up another WoW.exe, but do not go back to your other WoW instance until the login screen comes up. (Or the 3D acceleration error will come up, retry if it does)
4. Rinse and repeat for more instances of WoW, based on RAM and/or computer quality.
Sorry if this doesn't work for anyone else, was posted already, or is common knowledge.
Different realmlists:
Edit your realmlist after step 2.