Tri-Booting Windows 7, windows 8 and Ubuntu

Hello everyone,

I have searched numerous solutions for my problem yet I am confused. Please help!

I am currently running Windows 7 and Ubuntu (Windows 7 on C:\) by default.

I want to install another windows 8 Instance. (I can extend my C:\ and make another drive for windows 8)

Please help me how do i do this? Because, I don't want to loose my windows 7 nor boot manager in this process.

Thanks for your help!
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