I've seen numerous online retailers selling OEM versions of XP Home and XP Pro - buying these can essentially halve the price of the full retail version. Is there something I'm missing, or would you have to be mad to buy the retail version? Is there some support issue that I'm missing out on, or is it just as good, only cheaper? I'm curious as I'll be building a system this summer, and I'd rather save myself a wad of cash by buying the OEM version, so long as it's more or less the same thing. Hope someone can help!