Welcome to LQ.
You'll need to use the Windows' fdisk util with the undocumented switch
/mbr:
fdisk /mbr. If you are intending on installing Windows, then you shouldn't need to do this, since the installation will sort it for you... you should only need to do this if you have an existing Windows installation. Alternatively, you could try a 3rd party bootloader, such as
XOSL the eXtended Operating System Loader.