The Dell branding does not mean that it will not work. The Dell DVDs activate only on OEM keys, so if you have a PC with an OEM key on a label (which is typically for the big manufacturers) a clean install should work and once you enter your OEM key it should activate.
If you don't have an OEM key label or a legitimate key to work with you are pirating Windows no matter what disk you use.
There are really 5 types of activation for Windows Vista/7: OEM, Retail, Upgrade, Enterprise KMS, Enterprise MAK. You should be aware that OEM keys only activate on one cpu type either 32 bit or 64 bit but not both, whereas retail would activate on both.
They also aren't a generic Windows image anyway - they have the OEM specific stuff on them!Actually, the Windows discs are generic, at least the can be. They do indeed usually have OEM-specific stuff (like tons of shareware junkware), but they can be a raw Windows disc with nothing different other than the key built-in. – Synetech Dec 07 '12 at 18:26Those manufacturer specific discs have something that they look for in the BIOS I think. I'm not exactly sure what, but somehow the manufacturer "signs" their computers and the disc looks for that signature.It’s called the SLIC; it is a signature in the DMI of the BIOS. If you are going to use the OEM key, then you must have it in place, however its presence does not prevent you from using a different key you bought separately (at least not before Windows 8). – Synetech Dec 07 '12 at 18:36