My friend has a Gateway FX laptop or something with Vista. The right speaker stopped working (i checked all the balance settings). I've searched around for how to change the output from stereo to mono, but they all say the same thing; set it to mono (laptop output) in the sound settings. This laptop has no mono option, only 2-channel stereo. Any suggestions?

Do you have the latest drivers from Gateway?

check out the wires on your speaker might be loss, cut or what..and also checked the connector of your speaker it might be damaged..try using other speaker if same thing is happening..or else check out the settings in your control panel --- audio devices -- whether you accidentally change the settings to either left only or right only,,make sure that the position of the slider bar is at the center..good luck..

I have a problem with my audio to can anybody help me about it

what problem?

Don't know if you still have the problem... Making the assumption that your control panel is set to Classic Mode (just go to the CP, should be a setting) go to Sound and Audio Devices under "Speaker Volume" click "Advanced", then in the drop down, select "Laptop Mono".