Windows boot option is missing after installing CentOS 7, how can I get it back?

I recently installed CentOS 7 on a machine that has been running Windows 7. I did a dual boot installation and installed CentOS in a partition. But when I boot up my machine, it only gives me two CentOS options. It does not give me the option to choose to boot Windows 7. How can I add windows 7 back to the boot options?

How do I change the GRUB boot configuration from within Windows?

I currently dual boot Windows 7 and Fedora 14, using GRUB, with Windows 7 as my default. I know that from Fedora, I can set GRUB to boot into Fedora, overriding the default, on the next reboot. Is there a way to do this from Windows? That is, can I change the GRUB configuration permanently or semi-permanently from Windows so I don’t have to be in front of my computer to boot into Fedora?