Change Grub Boot Order

1. Grub only gives boot options and launches the appropriate boot loader.
   Thus putting it on the SSD will not speed up booting since the actual boot is done from the drive with the OS on it.

2. Edit /etc/default/grub. Change GRUB_DEFAULT=0 to point to the menu entry you want to be default.
   For example: GRUB_DEFAULT="Windows 7 (loader) (on /dev/sda2)"

3. Windows can not change the grub boot order.

1. For faster boot up... assuming that Ubuntu is your primary OS... with your configuration... the best you can do is to install Ubuntu on the SSD, but with the /home directory on the 3TB HDD. Make sure that you've formatted the 3TB drive with a gpt partition table, as it's over 2TB in size. You could also partition the 3TB with an extra NTFS partition so that you could easily share files between Windows and Ubuntu.

2. See item #3, below.

3. If you edit /etc/default/grub with the following settings, it'll remember the last OS you booted, and that will become the default OS for future boots.

In terminal...

gksudo gedit /etc/default/grub

add/change these lines near the top of the file...

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true

save the file and quit gedit. Then...

sudo update-grub

Here's a tip based on what I was searching for when I found this question:

The order of the menu entries when you run update-grub is controlled by the order of the files in /etc/grub.d

If you want Windows to come up first, move the entry for os-prober to a lower number than the entry for linux.