The driver is almost certainly your problem. Drove me crazy until I figured that out. The drivers are on the Dell utilities disk, but they are hard to find. As I recall, I found them in the files for the Dell Connection Manager. I had to install this application to get the drivers and then later uninstalled Dell Connection Manager which I found to be a very annoying little program.
‘then later uninstalled Dell Connection Manager which I found to be a very annoying little program.”
its a PITA. Has to be the worse application I’ve ever received on a pre-built computer.