How to Install Windows 7 on a UEFI enabled Computer

We recently bought a Lenovo T-440s amd immediately loved it, except it came with a Windows 8 Professional, 64-bit. It had "downgrade rights" for Windows 7 Pro 64-bit. Unfortuantely, our corporate IT environment does not (yet) encourage Windows 8 especially in laptops nor desktops, so I really was obligated to downgrade it to Windows 7 Pro/Enterprise.

The T-440s is Windows 8 optimized and is UEFI and secure-boot enabled. As an IT professional, I am also interested in how UEFI works (later I'll write a blog after I successfully installed Kali Linux on dual-boot in a UEFI system) and if it indeed delivers to is promise. UEFI is explained in detail here. Microsoft also explains UEFI and how it is here.

Do note that UEFI systems behave differently depending on the model and brand of the computer. This how-to post is specifc to the T-440s. While the concept and the general procedures may be the same as with other laptops (i.e. Acer, Asus, HP, Dell, etc.) the behavior may differ slightly.

The Objective:  Install Windows 7 Professional 64-bit on a UEFI enabled Lenovo T-440s.

Before we begin, let us first discuss what are the differences between installing Windows OS in UEFI and in non-UEFI mode (aka Legacy Boot Mode)

1. UEFI installation of Windows 7 only works in 64-bit installations. 
2. UEFI does not work in Win XP. 
3. By default T-440s ships with Windows 8 and with UEFI and Secure Boot enabled. However Windows 7 normally is not for UEFI systems.  If your Lenovo Thinkpad T-440s ships with Windows 7, the settings may have been changed. 
4. The Lenovo Thinkpad T-440 does not have a CD/DVD Drive, you have to either attach a removable drive, or create a EFI-bootable Windows 7 USB Stick. 

Here's how:

1. Go to the BIOS Setup by rebooting your Lenovo Thinkpad T-440s then, repeatedly press F1 until you get to the BIOS Set-up Screen.