I have Windows 7 (my primary OS) installed on my SSD, and I recently installed Ubuntu 12.10 (I only use it occasionally) on a partition I made of my HDD which I also use to store files on.
My BIOS is set to start my SSD by default. Whenever I boot, I see the GRUB menu asking for which OS to boot (Windows 7 or Ubuntu and other recovery versions of Ubuntu).
I want Windows 7 to boot automatically, and never show GRUB menu again. I want to be able to boot Ubuntu when I need it from my BIOS by selecting my HDD or the partition I made for Ubuntu from the boot disk selection menu in my BIOS.