New
#11
Most consumers only need Home Premium. The best price I see for it from a legit major retailer is on Tiger Direct. MS is only making OEM copies available now because they think Win7 is phasing out, even though all of business is moving off of final XP into Win7.
You have 30 days to activate with Product Key for exact same version you install. You can reinstall Win7 retail version as often as you please.