may have some technical problem inside it
You can get laptop speakers at any store that sells laptops or laptop accessories. Instructions for installation should always be in the package of the speakers when purchased.
Speakers that are inside/on the laptop
The Alienware laptops actually have great speakers on them.
If you have purchased a set of speakers to replace the poor ones your laptop originally came with, installation is simple. Most of them are USB speakers, so all you have to do is plug the cord into the USB port on your laptop and your sound will play through them.
in the headphone jack
Yes, you can purchase external speakers for your laptop from companies such as Altec Lansing or Logitech. You will just need to connect the speakers to your laptop using a USB cable, which will be supplied with the speakers. Some speakers come with a separate electrical power cable, while others use just one cable for the sound and power.
It depends on the brand of laptop and the problem with the speakers. The most likely cause is that a connection has come loose somewhere and the speakers are fine. If you were to replace them the best way to do it would be otaining a broken laptop of the same model and swapping them.
Wireless speakers tend to cost more than traditional speakers because wireless speakers use more advanced technology. Wireless speakers are less restrictive as in they can be placed anywhere in your home and can even be transported more easily when you travel with the laptop.
because
For credible brand of laptop speakers it is recommended to purchase it from Sony Houston Galleria which has a good quality not only on product but in the name itself. There are many choices to choose from from small to larger speakers.
Quite often by the USB plug on the speakers. If by non-powered you mean powered by batteries, then normally by the AV/headphone connection on your laptop.
Best Buy and RadioShack are great sources for reasonably priced laptop speakers. If you prefer to shop online, Amazon and Newegg also have great selections.