1. No, no functional difference.  Some OEM branding is the only difference between an Dell installation DVD and a generic installation DVD. 2. You don't even have to pay for the installation DVD's, in fact, you don't even need to use them (although it can simplify installation). You can order a replacement disk here:[URL] Or you can download a "retail" version of Windows from Microsoft's online partner, Digital River, then activate using your Product Key (may require you to activate over the phone:[URL] 3. The Product Key is the alpha/numeric code you need - five blocks of five characters, something like this: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX This is what you will use if ever asked for an activation/product key, and is your actual license to run/use the Windows software. 
Hi, trying to reinstall windows 7. When I purchased my computer (XPS 8300) I elected to not take the backup disk, so I had the idea of simply downloading the installation files and burning them to a DVD(s).  But before I take the plunge I had a few questions- 1: Aside from software and services associated with Dell's version of window's 7 (IE: Datasafe local backup, ect) is there really any difference between this and any other version of Window's 7? 2: Is this even doable, or am I really just stuck paying Dell for the re-instalation DVDs? I've been using the factory restore function thus far but at some point I can see myself needing to do a clean installation.  3: a certification key is not a certification key is not a certification key. I know there's a lot of different variants and looking at the Microsoft certification sticker on the top of my case there's three different strings of numbers that really mean absolutely nothing to me. Which is the one I need and which ones are just there to confuse me? 
Reinstalling Windows 7 OS - question