YOu don't reformat an OS, you reformat a partition on the hard disk. And then it's empty.
If you want to install an OS on it, go ahead. Vista (like XP) supports formatting as a first step of the setup, so it's easy (and best) to combine the format and the install.
Then install all drivers, starting with the motherboard drivers. Your memory is wrong.
If i completely reformat Windows Vista, everything will be erased including the installation for the mobo, correct? Than that would mean i would have a blank computer with nothing except for an OS installed. But that does not make sense to me. From what i remember, i had to install the mobo first, before installing the OS. So how is that possible?