With regards to your questions about the speaker volume, you may want to do the following:
1) Check the connection between the speakers and the PC. Are they secure? If not, secrue them.
2) Also check if within the Windows environment - whether you've enabled the sound to maximum. Sometimes you need to up the master volume and also the WAV file volume.
3) The other thing to do is to try the speakers with a normal Hi-Fi or another computer. Do you get the same problem? If you do, then its the speakers that are defective. If not, then the Dell has a problem. You may want to get an additional sound card to help matters.
Laptop speakers aren't very powerful. There are media player EQs that can effectively double the volume by playing with the voltage, but it would certainly sound very bad at that point. For a few dollars you could get something at your local electronics store that would turn up a lot louder than built-in laptop speakers.