Are you saying that the GRUB2 entry is missing, or that the entry is there, but Windows is unable to boot?
The Windows entry is usually detected by the GRUB os-prober script. I believe it's located in /etc/grub.d/30-osprober or something like that.
You can force GRUB to autoupdate the config and see if that fixes the situation.
# cd /boot/grub/
# cp ./grub.cfg ./grub.cfg.old
# grub2-mkconfig -o /boot/grub/grub.cfg
If that doesn't populate, you can manually specify the Windows 7 partition in one of the custom entry scripts (I think 40-custom or 41-custom in /etc/grub.d/). This only works if you didn't overwrite the Windows Bootloader
since it relies on chainloading.
Edit: Post your results of running grub2-mkconfig, and if that isn't successful I'll post a custom entry