I divided hard drive in two, that will be driver C: and driver D: what I want to do is to install Windows xp in drive D: because in drive C: Windows 7 is already installed.
there are ways to do it with grub/linux loader but its not for regular users your best option is to use VM ware and run xp inside win7 don't know what are you trying to accomplish.
Also if its a must you have to install xp first then install windows 7 i have not fiddled around the other way but if you install windows xp later it will over wright the MBR then you will have to re-run win7 disk and repair the startup after that edit the startup files and give option to boot xp at startup sounds complicated i am not liable if you mess up