I recently installed SUSE Linux Professional 9 and 9.1 on a Windows XP machines. The hard disk was 40GB and Windows owns 10GB of it. The Linux distributions were installed into the remaining partition on each machine.
Both SUSE 9 and 9.1 automatically added both operating systems to the GRUB boot screen. This means I can choose to run either Linux or Windows XP at boot time without having to manually fiddle this are you need to do.
My solution to your problem would be to set the Linux partition as the active partition, then add to your GRUB control file:
Where x is the partition that Windows is installed in starting at 0 as the first partition.
Note: This assumes that RH7.1 uses GRUB. If it uses LILO (ie: there is no /boot/grub/grub.conf file), I suggest you join the Red Hat mailing list and ask for help there.
Alternately, you could leave the Windows partition as the default boot partition and simply add the Linux partition entry using a tool such as BootPart.
This was first published in July 2004