Just got a new Dell XPS8500, which came with Windows 8 OS.

 My first preference was to have Windows 7 Pro as the OS. I did an online chat with Dell and was told that the system I wanted came with Win 8 and if I wanted Win 7 I could order and install it myself. So, I purchased a new retail copy of Windows 7 Pro.

 I want to setup a dual boot configuration for Windows 7 and 8, with Win 7 as the default.

I plan on using Win 7 for the next few years and transition to Win 8 later.

 Unfortunately I understand that when you setup a dual boot configuration you have to install the previous (older) version first, which would mean that I’d have to clean install Windows 7 first and then install Windows 8, sounds scary. Is this true?

 Because the Windows 8 OS is an OEM a disk was not provide.

I know if I do a clean install of Win 7 I'll loose the Win 8 OS. Is it possible to setup a dual boot configuration without loosing the existing Windows 8 OS?

If you do a clean install does it overwrite only the existing OS data and leave other program files alone?

 Any help you can provide is greatly appreciated.