I cant download a single addon without have the client but the client wont let me use the path C:\World of Warcraft\Interface\AddOns and im using vista and there is not a game folder in my public folder.  I go to download manual install the open box pops up then nothing... I have no mods and its really starting to make me mad can i get some help please

i have forgotten my log in name and pass word.  I can not get the addons for wqw.  Could you please help me  my e-mail is deann.johnston@comcast.net