Dell Dimension 5000 Sound Problems

[JamesWoodhou]

Hi all,
I received a new Dimension 5000 Desktop from Dell on 8th April.
For the first week or so everything worked fine but since then I have had problems with the sound.
These are the symptoms...
80% of the time when I boot up and log into XP there is no sound although everything is connected. No system sounds are heard nor any music, etc. if I play a CD or a game.
Then after a while (maybe a few minutes, maybe longer) the sounds suddenly comes back. I have played CDs through Media Player and the patterns appear so everything looks to be OK, just no sound.
Once the sound comes back, everything is fine until I shutdown the PC. At the moment I am keeping it on all the time.
I have tried the following troubleshooting...
1) Ensured everything is connected properly with no loose wires and everything lit up as it should be
2) Checked Device Manager to make sure the device appears and there are no exclamation marks against any devices
3) Uninstalled all software I have installed since receiving the PC
4) Restored the PC back to the point when I received it
5) Tried another set of speakers
I receive no error messages at all when no sound is heard and the PC runs normally, just without any sound. Very mysterious that it suddenly comes back.
If anyone has any suggestions or can help in any way, please let me know asap.
Hopefully this won't result in having to send the PC back to Dell.
Thanks.

[QmunkE]

Can you post a list of your currently running processes (use http://www.merijn.org/files/hijackthis.zip and post the log it generates here)