8
if you buy 7 oem its locked to the first mb you install it on .
If you buy win 8 64 bit you get a home user license that lets you transfer it to two additional motherboards [ only one at a time ]
Once win 8 is up and running right click all the metro apps you dont want and uninstall them . Gone for ever and wont bother you .
Then download and instrall Classic Shell to add a start button and it behaves almost identically to win 7 .
Takes about 6 minutes to make it work the way you want