I just built my first PC, and I am definitely getting Windows 7(or 8) however I don't have the money to just go get Windows till next week. My question is do I need to have windows first? If I install Ubuntu before Windows can I still install Windows after? All I have right now is the Asus system BIOS and I have never done this yet. really appreciate your time and answers you guys can provide for me. Thanks
You can install Linux first and after that Windows.
I am not sure if windows is now capable of detecting already installed boot loaders. When windows is overwriting the linux bootloader you have to start your linux system from a live cd and reinstall the bootloader. Linux bootloaders can detect other operating systems and can start them.