Try each suggestion below, skip the ones that may seem irrelevant
Make sure the speakers are plugged into the green jack. Also make sure it securely plug in and powered (If amplified).
To Display The Volume Icon
By default, the Volume icon is not displayed when you initially installed on your system.
To enable the display of the Volume icon, follow these steps:
1. Click Start, and then click Control Panel.
2. Double-click Sounds and Audio Devices.
3. Click Show volume control on the taskbar.
4. Click OK.
When you have the new desktop features enabled, follow these steps: 1. Click Start, and then click Control Panel.
2. Click Sounds, click Speach, and then click Audio Devices.
3. Click Sounds, and then click Audio Devices.
4. Click Show volume control on the taskbar.
5. Click OK.
If that doesn't work then try this.
Go to "Start".."Control Panel"..."Internet Options"...Click the "Advanced Tab"...scroll down to multimedia and put a check mark in play sounds on websites.
Then go to "Tools"..."Manage Add ons"...and make sure everything is enabled.
Then close Internet Explorer and reopen
or
Go to Start -> Run -> and enter Services.msc
Scroll down to "Windows Audio".
Double click and change the startup type to Automatic
or
Go to the manufacturer of your computer website and download the necessary free audio driver.
If you own a HP or Compaq visit http://www.hp.com and visit the support area
Toshiba http://209.167.114.38/support/
Dell http://support.dell.com/support/topics/global.aspx/support/product_support/product_support_central?~ck=ln&c=us&l=en&lnki=0&s=gen
Gateway http://support.gateway.com/support/
Lenovo http://support.lenovo.com/ca/en/DriversDownloads/drivers.html
Intel http://www.intel.com/support/index.htm?iid=hdr+support
AMD http://www.amd.com/us-en/SupportDrivers/ProcessorSupport/0,,15218_15219,00.html
eMachines http://emachines.com/
Ibm http://www.ibm.com/support/us/en/
Acer http://www.acerpanam.com/flex/acer/bin/acer.html#app=2766&9e7c-selectedIndex=0&3386-selectedIndex=0&7ac3-selectedIndex=0&f3bf-selectedIndex=0&c985-selectedIndex=0
Cheers