Quote Originally Posted by ITAvenger
In your WTF folder there is a Config.wtf file that you can edit in Wordpad.

You can change the SET gxResolution "800x600" to whatever you'd like. If you've got the windows on top of one another you'd set the config file for each instance of WoW to SET gxResolution "1680x525"
just make sure to not make changes to video settings in game or it will revert it to the default if you have a non-standard resolution. ie make changes to things like graphics qaulity, gamma and so on in game then change the .wtf file for the resolution you like and dont mess with it again.