Hi. The method that you described is what I've been talking about, and I've actually tested it. I converted a retail XP Home disc to OEM, and used it to install onto an eMachines computer, which has the same version of Windows installed. This is obviously not a branded type, so the only other type it could be is generic OEM, and it DOES work with the license key on the eMachines COA sticker, when activating Windows.
I'd like some generic OEM copies of Windows like this, so when I help people, if they have lost their install media, and the manufacturer can't help, I can just wip out my own install media without having to look online and go through a hassle. Of course, any installs I do would be using legit product keys, directly off the COA stickers from their computers.
I do have legit retail copies of XP Pro, and Windows 2000 Pro.. I just need XP "Home", "MCE", and "Tablet"