I bought an SSD for my laptop and I moved the old one on the optical drive bay. I installed windows on my SSD and then installed ubuntu on the old one (sdb). I installed Ubuntu using manual partitioning and installed grub on the windows hard drive (sda) and now I'm not able to boot windows anymore nor to find it using grub-update.
os-prober gives me only ubuntu:
sudo os-prober /dev/sdb1:Ubuntu 14.04.3 LTS (14.04):Ubuntu:linux
Windows is on sda.
How to fix this?