Audio Through Integrated Speakers

I have been handed down with a DELL Inspiron 700m, Laptop. I have a few questions on how to use it. I am no great Computer wizard.
1. There is no audio which can be heard through the Laptop's own sterio speakers. Absolute silence. But, when I connect the headphones, everything is Hunky Dory. How do I hear sound through the Laptop's speakers.
2. Is there any separate volume control device as in my previous LG laptop? Or, am I to go into the volume control page and reduce/increase the volume? or only through the F6/F7 keys?
3. I have the latest Mcafee Antivirus whch, as of 30 min back,scanned and said no virus. I have defragmented fully,cleaned up the hard disk, etc. But still the comp is pretty slow. Out of a total 52.8GB( God knows what is this odd figure) of memory,40.4GB are free, at least as per the laptop itself. So there is no overloading. Then why is the speed very slow and how do I make it better?
Would love to have the answers from anybody.

 

The laptop speakers may be on mute. The volume control panel should display all volume controls although there may be an another application with volume controls like Creative software.