I have a system that dual boots with Windows 7 (64 bit) and Windows XP (32 bit); each OS is on its own hard drive. I want to reformat the Windows 7, deleting the OS in the process. What I'm wondering is where is the boot loader located? Is it on the Windows 7 drive (since it was installed after XP), and will I need to do anything special to have the system load Windows XP by default after the Windows 7 installation is gone? Will the system simply detect the old XP installation and load it without the bootloader?
open the run dialog (windows key + R) and type MSConfig.
Under the boot tab, see if there is one or 2 OSes listed. If there is only one, then the boot files are on the other HD. I think they'll end up on the XP hard drive.
You'll want to delete the boot files from it before you reformat the drive.
You can always just unplug the drive w/ Win7 and see if XP still loads nice, if it does than you can go ahead w/ whatever u want.