I have returned after an extended time away and can't remember if the mouse can be switched from normal to inverted. I can't seem to find it under any type of options, any feedback would be helpful.
If you mean left-handed vs. right-handed mouse, that's done in Windows' Control Panel / Mouse. I don't know how to do it for other operating systems.
If you mean you want to change the y axis movement, so that moving the mouse upwards moves your character backwards and vice versa, I don't know of an in-game setting for that. In the Bin directory of Wizard101 is a Config.xml file with some mouse settings, but I don't know which does what. If you do decide to play with that file, be sure you make a backup of Config.xml so you can restore things to normal if it doesn't come out right.
