i am afraid you have to reinstall wow
ram shouldn't really have anything to do with it, it just seems like his windows install is messed up, that happens from time to time.This
I had an problem like that, but when i clicked wow.exe the launcher came up.. and when i clicked play, the launcher launched again..
EDIT: I also reinstalled my os (Win7) I didn't read throuh the threades, but i have mine installed on SSD, and it works like a charm now,
If not that, try to remove one ram.. can't help you any further.. sorry