[ubuntu] Trouble booting to Windows on 2nd HDD

You may find that the Windows drive must be in the laptop and recognised as sda if Win was installed in the laptop on that drive when you bought it. In fact, many laptops will ONLY boot from sda and you need to do some serious hoop jumping to get sdb to be the boot drive.

I did something similar to you and put an SSD in a hard drive bay where my optical drive bay used to be, cloned my Ubuntu install to that and then tried to get that to be the boot drive. No way. I spent some hours on it and my workaround is selecting the boot device menu with F12 at boot, choosing the FDD(!) entry, that takes me to a grub list, I then scroll down that to 'sdb' at the bottom and I'm there.

Hopefully someone can chime in with an easier workaround, but the 'boot from sda only' scenario makes things difficult, if that is the case with your machine.

Besides all that, most pain-free seems to be Win owns the first partition, first drive and is installed on the earliest available partition, first drive: sda. Windows doesn't like to be on other drives. You need to coax it.