Hmmm ... punjabian263, I think you are asking what sequence is required?

Normally, you would install Windows (whichever version you will use) first. Then install the posix-based OS (Linus, Unix, Solaris, whatever-nix). The posix-based OS will give you the option to install and configure a boot manager (lilo or some other) so that you can select the OS to run at boot time.

Hope that clears that up.