Windows 7 Family Pack Cleans With No Media Loss.
One way of doing this is to boot from the Windows DVD, decide to install, and select the accessible boot divider. This will set up a new duplicate of Windows, but in an another folder to the unique copy. People used to do this by mistake, and you would finish with both a Windows.0 and Windows folder. These days the procedure is somewhat cleverer, and keeps your files, but makes the old Windows fixing non-bootable, which prevent the double boot startup choice appearing for both installations.