What type of windows is required for bootcamp?

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If you haven't got Windows, you have to purchase a System Builder or full version. You can get them at Amazon or NewEgg. System Builder is cheaper but you can only use it in your Mac. However, with a full version, you can use it in one computer, but then you can use it in another computer if you remove Windows from the Mac.

The upgrade version is only for users that already have Windows installed

I bought a full win7 uptimate 64bit version and installed it back in bootcamp in the lion days

then I updated to mtn lion and later on I bought the win8 pro digital upgrade and installed that ontop on win7 it works fine