My speakers do not work for some reasons. I checked they are fully plugged and light up to show they are on. But when I watch or listen to anything they do not work. I though maybe they got switched off in control panel. I checked it says no devices installed what can I do? ALso They are brand new so it can not be them.

Me computer is a Microsoft Windows Vista Acer Aspire ast180

Just because they're brand new doesn't mean they aren't DOA. What are they and where did you get them from? Also, what are your computer's specs?

Did they come with a driver CD? If so, install the audio drivers for your speakers from that. If they didn't come with one, go to the support section of the manufacturer's website, you may be able to download the correct drivers from there.

You don't need drivers for speakers, do you?

Yeah you do, it's just normally the default Windows audio driver is used when you plug them in, meaning you don't actually 'see' any driver installation process. However some speakers do come with their own audio drivers, which can be better to use because they're designed specifically for that model rather than as a general driver like the default.

If they are properly plugged in like you said and Windows doesn't even recognise them as an 'unknown device', the speakers may just be dodgy as Caboose originally suggested.