This is how you can restore Grub with a default Fedora 19 installation. Grub will recognize your Windows 7 installation.
Boot from the live DVD and open a terminal as root. First use fdisk -l to identify your partitions.
This example is from a system that uses default partitioning of Fedora 19.
[root@localhost ~]# fdisk -l
Disk /dev/mapper/live-rw: 8589 MB, 8589934592 bytes, 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/live-osimg-min: 8589 MB, 8589934592 bytes, 16777216 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0003948c
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
Disk /dev/mapper/fedora-swap: 2164 MB, 2164260864 bytes, 4227072 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/fedora-root: 18.8 GB, 18782093312 bytes, 36683776 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Use this output for the following commands.
mkdir /mnt/root
mount /dev/mapper/fedora-root /mnt/root
mount /dev/sda1 /mnt/root/boot/
mount -o bind /dev /mnt/root/dev
mount -o bind /proc /mnt/root/proc
mount -o bind /sys /mnt/root/sys
mount -o bind /run /mnt/root/run
chroot /mnt/root
grub2-install --no-floppy --recheck /dev/sda
grub2-mkconfig -o /boot/grub2/grub.cfg
exit
/sbin/shutdown -r now
