An assembly includes an article, and a computer housing including left and right sidewalls cooperatively defining an accommodating space and an opening for communicating the accommodating space with an external environment, and a positioning member provided on one of the sidewalls. Each sidewall includes a slide rail. A package is mounted removably in the accommodating space via the opening, is connected slidably to the slide rails of the sidewalls, and is positioned within the accommodating space through the positioning member. The package includes two interconnected cover parts cooperatively defining a receiving space for receiving the article and a communicating hole for communicating the receiving space with the external environment, and a handgrip to mount removably the package in the accommodating space. Each cover part includes a stop member abutting against the article to prevent escape of the article from the receiving space via the communicating hole.