Directory writable by server

I know this has been asked several times before, but I couldn’t find a straight answer.

I’ve been trying to upload plugins and media, but all of a sudden I started getting the page to add my FTP credentials and the Unable to create directory wp-content/uploads/2013/07. Is its parent directory writable by the server? message. It let me upload plugins before then this started happening all of a sudden. It’s a new installation and this literally started happening a few hours of being installed. I’ve messed with the CHMOD for wp-content and it doesn’t want to work. Does anyone know how to fix this?