External Keyboard and Windows Vista, Installs but wont respond?

I have a laptop. At home, when I set it on my desk, I would prefer to use a normal sized keyboard and mouse. I purchased a Emprex 5105U keyboard that uses a USB cord. I plug in the keyboard, windows detects the keyboard, installs the software and notifies me it is ready to use. Although, when I go to type ANYTHING on the external keyboard nothing works. Not even a light comes on when I press caps lock. NOTHING. I went to device manager to try to uninstall my laptops keyboard, but windows just keeps reinstalling it. There is not a disable function. I have all of the windows updates and yes my drivers are up to date as well. The only thing I have noticed that makes a light on the keyboard come on is when I hold Fn and Scroll (which locks the Fn option on the keyboard on my laptop) but on the external keyboard it just lights up one of the lights and still nothing else works. Am I missing something? I also tried it with a HP Multimedia keyboard. Both I bought NEW from Best Buy, so I am the only one that has every used it. New out of the box. Any suggestions?