Won't Download while playing

Hello everyone, first of all, i'm sorry for my bad english. it isn't my mother language, and now to the topic..
i've been experiencing problems with the retail downloaders, it is not downloading while i play, it stills at 0% even trough i have a 20mb internet conection, it has to download everytime i go to somewhere new, and stills appears as 0%, gets laggy sometimes when the download icon appears red. i tried with the firewall, others download links, and patching it up, and stills nothing. a friend of mine downloaded the same retail and his works perfectly. thanks for yor attention, and thanks for the help. have a good day!.

Do not worry about the percentage, do you experience any improvements in the loading screen speed from the first time you started the client? Less downloading circles?
If so, the download is progressing. Otherwise make sure that your files are not read-only.

indeed, the download screens are faster than before, and there are less downloading circles, but i just noticed i can't take off the read only property.