update-grub

Generating grub.cfg ...
Found background image: /usr/share/images/desktop-base/desktop-grub.png
Found linux image: /boot/vmlinuz-3.2.0-4-amd64
Found initrd image: /boot/initrd.img-3.2.0-4-amd64
grub-probe: error: cannot find a GRUB drive for /dev/sdc1.  Check your device.map.
ls: reading directory /var/lib/os-prober/mount: Input/output error
ls: reading directory /var/lib/os-prober/mount: Input/output error
ls: reading directory /var/lib/os-prober/mount: Input/output error
ls: reading directory /var/lib/os-prober/mount: Input/output error
Found Windows 7 (loader) on /dev/sda1
Found Windows Recovery Environment (loader) on /dev/sda2
done