Try the simplest stuff first.
Check the batteries if there are any in the speakers.
Check that the electrical plug is not out of the wall socket or rear of the speakers.
Check the plug is still seated in the rear of the computer.
Many speakers have a small light on one of them see if yours is lit if there, this will indicate whether you have power or not.
If you have a headset plug it into the computer (not into the speaker) and try a music CD to decide if the problem might be inside or outside the computer case.

All the above seems good?
Click Start
click Control panel
click Sounds, Speech and audio devices
Look around here, your system may be different than mine so specific details will not help.

Any help so far?

Thank you very much for your suggestions, but I have already tried those things and nothing seems to be working. I have a light that goes on and when I turn the speakers on, I get a crackling sound but nothing else. I have turned up the volume, but still nothing. Perhaps it is time to get new speakers.

so you get music and sound in your headset when connecting it directly to the pc? so you know for sure it is not your sound card?

do you have any other computer you can try the speakers on?
you checked the audio mixer to make sure nothing has got muted some how?
and of course my first thing to try is rebooting.

Thank you all, but I still cant get any sound from the speakers. It is very frustrating, but I guess I will have to get a computer repair person in to take a look at it.

Both Raven and myself asked about the results of using a headset and you never answered that. Help can only be as good as the information provided by the poster with the problem.

Did you use a music CD or connect to an internet radio station to see if sound was there in the headset? What happened when you used the information in my second paragraph?

Another area to look:-
Click Start
click Control panel
click System
click Hardware
click Device manager
now scroll down the list, you are looking for 'Sound, video and game controller'. Do you see any yellow question mark or exclamation mark there? These will be large and easily visible if present.

Try going to Start/Control Panel/Sounds and Audio Devices. Then check the Volume tab to make sure it's set to an appropriate level and the Mute box isn't checked.

Also check the Audio tab and make sure the Default device is the correct device. If you've installed anything like an IP phone or a bluetooth device, they will sometimes set themselves as the default device when you install them..

Well I am still having the same problem, no sound. I have tried playing a CD but nothing comes out. I tried what you had suggested Obist and got as far as systems and could not find hardward. So thank you all very much for trying to help me, but I guess I will have to get my computer person in to see what else I can do.

mystic,

Have you tried rebooting your pc?

Before paying someone to fix it give 'System Restore' a try.

Witz

System restore will probably work or: You can do the exercise below.

Go into Services (right click on My Computer, select Manage. Open Services and Applications and select Services). Scroll down the list till you see Windows Audio and double click on it. Service Status should say Started. If not click on the Start button, Apply and OK.

Windows xp also has a good sound trouble shooter built in..

Click start, click control panel, over on the right you should see help & support click it - window opens towards the bottom you will see "Fixing a problem" click it 3rd one down where it says "Games, sound, video, click it - window opens 3rd one up from the bottom where it says "Something is wrong with the sound on my computer" click in the circle and choose next and follow the prompts

Do you by chance have a monitor with volume controls on it? If you do check those as they often work independent of the system controls.

Do you hear the typical Windows sounds when completing tasks?

DA