2) i'm also pretty sure (but try it out) that Dell;s install discs will only work if you install on a Dell. You won't be able to use it (or maybe just its product key) if you install a new build (ie. non Dell system)
Neither will work unfortunately.
I know from experience, as I was unable to activate my Dell Vista OS discs, or my Dell Win XP Pro, or my Dell W7 Ultimate discs on anything other than a Dell machine.
For example:
I have used my XP Pro disc supplied with my Dell Vostro 1500 laptop to install it on my Dell Vostro 420 PC in the past. I've swapped around Vista editions between Dell's with no issues at all, but I tried installing one of my Dell supplied W7 versions on my current Dell after replacing the motherboard and it wouldn't even let me install W7!
So I use a student discounted Windows 7 Pro 64bit license on my Dell now, and the Dell W7 Ultimate 64bit it did have is now installed on my Dell Studio PC - It installed fine as that's a Dell computer.
I've also tried using Dell supplied OS' on my other computers and none have worked. I've even tried using OEM (retail OEM) discs with the product keys from my Dell's on other computers and that doesn't work either.
So to sum up my experiences:
If its Dell supplied, it will install on
any Dell computer/laptop, but
only Dell's.