I don't have a multimedia sound controller

Hi Carmen,
Do you mean your computer has no actual sound card built in or currently installed, or did it simply become unrecognized by your system some how?
Try going into My Computer/Control Panel/Add Hardware and let the wizard application run a search. If you have one, hopefully this will reinstall it. If you know for sure that you have one and this doesn't work, let us know.
Good luck. Take care.