Can anyone advise about Dual Core PC?

I just bought a Dual Core PC ,mainly because I wanted to run 2 programs at once.Here my delimma.I like to watch video,shows etc online while doing another project (taking surveys ,answering emails etc)however when I try to do something else online my window that has a video playing disappears ,however the sound is still playing and I can bring Window back,is there anyway to keep window from disappering everytime I click on something..Can anyone advise about Dual Core PC?
try power menu:





http://www.abstractpath.com/powermenu/





I had kinda the same problem with Google Talk, I wanted it to stay on top of other programs. I found this and have found it to be very satisfactory in keeping what I want on top, on top; just right click on the program in the task bar, tell it to ';keep on top'; and voila, no more going behind other windows.