por Luis de Vasconcelos.
I tried installing the latest 2.4 DEV this afternoon and experienced a similar "broken" images/css problem. Haven't figured out the problem yet. (But it is a pre-release version so problems are to be expected...) The 2.1 instance that I have on that same computer is fine. Both sites are running on the same IIS and MSSQL instance.
Try installing a blank instance of the latest Moodle 2.2 build and see if you experience the same "broken" images/css problem with that version.