My Toshiba laptop probably has a disk configuration similar to your Sony. Typically the manufacturer puts a restore partition at the beginning of the disk followed by the Windows operating system partition.
GRUB uses a file located on your Linux system partition /boot/grub/menu.lst. This is a text file that can be edited with a simple text editor like Kate or vi.
The entry in my /boot/grub/menu.lst to boot Vista looks like this:
Actually I added the rootnoverify myself because it might be required. My actual menu.lst doesn't include rootnoverify.