Boot into linux. Look in /etc/fstab and see which partition windows is on. hda1 or sda1 is drive 0, partition 0. hdb3 or sdb3 is drive 1 partition 2. I hope you can grasp the concept. Drives and partitions both start out at 0, but partitions start out at hda1 or sda1. There is no hda0 or sda0.
In /etc/fstab there should be a partition that is NTFS filesystem. Look at what it is.
That is if windows is on drive 0, partition 0.
That is if windows is on drive 0, partition 2