Have more then 6 dead pixels on your Dell laptop screen? From notebookreview.com:
LCD screens are generally the most expensive part of a laptop computer. They’re also the most likely part to contain noticeable flaws in the form of the dreaded dead pixels. Each notebook manufacturer has their own policy on how many dead pixels warrants a return and replacement. The problem is, most people are not aware of this policy before they get their notebook and falsely assume that one dead pixel is good enough to ask for a replacement, but this is generally not the case.
…Sometimes it is quite obvious as to whether you have a dead pixel on your screen, but sometimes it might take a little while for you to notice. It’s best that you run a test on your screen right when you get your notebook to determine if you have dead pixels and then take the further step of deciding whether you want to try and return the laptop if there are an excessive amount of dead pixels. Download a free application called Dead Pixel Buddy to test for dead pixels on your screen. Please be sure to donate via PayPal to the developer of this application if you can spare the money!