gooberking: Most of my PC's are actually running linux. I build them but have a hard time justifying paying a hundred to several hundred dollars for windows. The disparity between their function just isn't as great as the price tag. There is a OEM version but the licensing gets tied to the motherboard which terrifies me.
H2IWclassic: I've changed motherboards and other parts without problems using an OEM version of Windows (okay, it was free from work but it is a valid licence regardless).
gooberking: Its the same mental road blocks that keep me from buying PC games unless they come DRM free like from here or if they were born that way like "world of goo." (I've been lost passworded and other weirdnessed out of enough purchases over the years) I do have one decent XP system to fall back on if something doesn't work but my personal system is running two linux distros and no windows.
H2IWclassic: Personally I don't mind a disc check but anything beyond that I don't bother with either.
Technically (from what I can gather) your not allowed to use the oem version on a new motherboard without getting it OK'ed. Reviews are littered with post recommending you call and tell MS that the MOBO "broke" and had to be replaced with a new one (I think identical boards are OK.) I don't much care for having to lie.
There was also a lot of speculation as to the legality of using such versions for personal use as they are intended for system builders selling systems who are then required to offer service support for the product. MS has appeared at times to admonish the practice, turn a blind eye, and even recommend it. Its a very fuzzy situation and that makes me a bit nervous that when I need it I won't be there. Anything that can be taken away if someone else feels like it makes me nervous. I am almost willing to bite on the 3-pack system upgrade for win7 but that won't get me windows on my personal system and I don't need to upgrade.
As for CD checks they are noninvasive but it is a bit annoying to have to hunt down CDs for every game you want to play. Its much nicer to just click a link and be off to it.
But none of this has anything to do with MOO which is awesome.