I know there have been many variations on this question and have certainly tried to do my research. I don't really know what I'm doing so I would rather not take risks.

I am trying to dual boot xubuntu and windows 7. I started out with xubuntu and just installed windows. Of course, the mbr got overwritten and windows didn't seem to recognize linux. So I booted to the live cd and rewrote the mbr. And of course, now I get the error "No Operating System Found" on startup.

I have been following these tutorials to help me out. community.linuxmint.com/tutorial/view/245 unix.stackexchange.com/questions/96977/grub-wont-install ubuntuforums.org/showthread.php?t=2036730

Specifically, I ran these commands: # sdb2 is the partition with xubuntu sudo mount /dev/sdb2 /mnt

# sdb1 is my boot partition
sudo mount /dev/sdb1 /mnt/boot

# not sure what this does, but ran it anyway...
for i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; done

sudo chroot /mnt

#once chrooted
grub-install /dev/sdb
update-grub

here's a link to my gparted https://www.dropbox.com/s/zpbbzh9z7k1l3pj/gparted.png

EDIT---

didn't realize that the drive letters are different in the picture than in my code (its sda in the pic instead of sdb). I have been restarting a lot and sometimes the drive letters change and make my usb into sda.