Thanks for the explanation. The dell latitude D610 is the main computer that I want to install on and it does not have issue with PAE. I only use the HP pavilion machine to test it out first.
The last time I installed Ubuntu 12.04 on the dell, I did not have wireless either. What command should I run after I install Ubuntu to find out the correct networking card please? I'll post back the result so you can tell me the correct command to activate wireless like you did with the HP machine.