Some people will have one bad experience and then hate a company forever, even if they don't deserve it. Not much you can do in that case. I wouldn't cover up the Dell logo.
And in fact I have owned several Dell laptops and they have been quite solid. In my last Dell laptop, which I carried up the Appalachian Trail, the hard drive decided it was time to go. (Shocker! All that bouncing around...) Dell cross-shipped me a replacement.
A few years ago when I had another Dell laptop which developed a keyboard problem, they actually sent someone out next-day to replace the keyboard right at my house. For free.