Having problems patching WoTLK and then running it

Hello. When I downloaded the WoTLK expansion, and after logging in to the game it said that I have to download a patch of some sorts. Alright, I press the button to "restart" the game and then when the 70mb patch downloads(instantly), I was getting an error message saying that the files are read-only and whatnot. I fixed that problem by right clicking the WoTLK folder and removing the read-only checkbox(this applies to Windows10, in case anybody comes across the same problem), but after running the patch it downloaded a bunch of different files, and at the end I wasn't able to play the game, because it said something like "there is no disk in D:". Am I missing something? any help would be appreciated.

you have to log-in by using your warmane account name, not email address.
be sure your client is still 3.3.5 otherwise you need to download it again