Dell discs are great... For Dell computers, otherwise? generally worthless.
I have Dell discs for ALL XP-pro versions & Vista-Buisness
and they all self-authenticate/activate on any Dell system.
Sadly the Dell Win7 doesn't do the same, it authenticates but doesn't activate, but gives you 30days to enter a CoA.
My HP discs require a key to keep them active for more than 15days
(They "authenticate" but don't "Activate" without a key.)
But I have another "corporate disc" that NEVER asks for a key that has so far worked on every system I've ever tried it on.
though rarely does it install generic drivers that work that isn't a major hurdle for me....
But I would NEVER download an OS... that simply inviting trouble.