Bean007 :
Next time you buy a laptop or pre-built desktop tell them you don't want all the bloatware and they'll gladly ship you a PC with no OS. You won't get a discount as the OS is included in the price and you're laptop will be a useless pricey paperweight until you buy a OS. However I doubt they'll do this as it's done right as it comes off the factory line but hey you never know.
Good luck with that. I've tried doing that with numerous laptop and desktop purchases for myself and clients and I always get the same answer which is we can't do that. There are a few exceptions but for the most part they won't do it.
And you DO NOT want to buy and install an OEM version. OEM versions only allow the OS to be installed on ONE COMPUTER, EVER. So if you change motherboards or build a new rig, you're ass out.
Retail versions will allow you to re-install or reactivate if you change hardware, like the motherboard, and have to reactivate, or if you get a whole new system. They just make you do a phone activation to get a new confirmation number and to verify that you're only using it on one computer. Regardless of how many computers you've previously had it installed on, as long as you don't have it on more than one at any given time, you're fine.