Ok... it could be a malfunction in your sound driver... unless you can tell me right off the bat, is it an intergrated sound device, or is it a "card" (looking at the back of the computer, do u plug it in next to all of the other "stuff" like "usb ports, internet plugs, mouse, keyboard", or #2 do you plug it in on the bottom most of the connections in the back (called PCI-slots) ) ... sorry man im just going by your age and taking a wild guess that you dont know differences between things
Anyway, do this:
1. Click Start
2. Click "Control Panel"
3. Make sure your viewing it through "classic view" as per links on the left of that window
4. Click "System"
5. Click the "Hardware" tab
6. Click "Device Manager" button
That'll bring up a list of hardware on your computer...
1. Go down to "Sound, video, and game controllers" and click the + next to it...
2. You will probably see a bunch of names like "Audio Codecs", "***** Drivers", and "***** Devices" (stars representing any words)... you wanna avoid those "codecs, devices, and drivers" that are included in the name and find the one that says "Integrated blah blah blah" without the names I previously mentioned... thats your sound driver...
3. Right click that name and click Properties
4. A "General" Tab will show up, and it will say if its working properly or not... if it is, just click "Troubleshoot" and go step by step thru the process... if that doesnt help, send me a PM and ill gladly help ya out.
For all I know, the plug for your speakers is probably faulty... try hooking up another set of speakers or headphones to it if you get a chance.