You need to do the following:
1. Move the wow client to the root of your driver (Ex.: c:\wow-mania)
2. Make sure that the file realmlist.wtf is NOT read-only
3. Add the client folder to the list of exceptions of your anti-virus
4. Start Launcher as Admin
Check our tutorial here:viewtopic.php?f=16&t=35
If you still have problems contact me on skype (I can answer faster there).