Check if the system sound drivers. Go to "device Manager" (right click on "My computer" - "device Manager"). If in the opened window, a missing component of the tree "Sound, video and game controllers" or in this paragraph do not specify the model of your sound card, then the drivers are missing and need to be installed.
Find out the model of your sound card and the manufacturer name. The marking may be printed directly on the card itself. Its name can be specified on the panel where is located the audio outputs. The model can be specified in the documentation for the computer. If identifying the manufacturer and failed, install free CPU-Z utility, which will test your hardware and show the name of the sound card.
Go to the card manufacturer by entering his name in any search engine. Download the latest version of the software. Install in accordance with the instructions of the installer and then restart the computer.
Plug the plug the audio output of the computer. Usually the hole for the speakers is green, however, depending on the model and manufacturer of the motherboard it may vary in color or position on the panel computer. If after connection dialog box opens to specify the type of the connected device, select "Speakers".
Test the sound. If the sound still does not work, check the volume settings of the system. Go to control panel sound card and change the item "Speakers" to "Headphones". Check whether the hole of the connected speakers is fully plugged plug.
If you want to connect another pair of speakers, you need to check whether it is the sound card. To do this, look for the appropriate menu items in the control panel of the driver (for example, "2CH speaker"). If this option is available, simply plug the male plug of the second speaker to the second outlet. Otherwise, you can purchase a splitter for the 3.5 mm Jack hole in any shop of the radio goods.