What are the advantages to install Windows 7 with UEFI?

I just received a Dell Precision M4600 and looking at firmware it seems it has UEFI support but it is disabled.

So due to the fact that I need to reinstall Windows 7 from scratch, do you suggest to enable UEFI boot? What are the advantages? Are there any disadvantages?

Do you suggest to enable UEFI boot?

Yes, for one very simple reason: It will make you used to the way that things are more than likely going to be done as standard on your next personal computer, and are already done as standard on other lines of personal computers such as Intel Macintoshes.

The advantages and disadvantages of firmwares are not directly relevant to end users most of the time. Several of the advantages touted in the Wikipedia page do not immediately impact an end user. End users only interact with firmware directly in a couple of places, including Initial Program Load and system configuration. Otherwise, there are several layers, such as the operating system, its device drivers, and its hardware independence layer, between the end user and the firmware. What you'll see are the secondary effects. Modern EFI firmwares are easier to develop for than old PC/AT and PC98 firmwares. System software can be designed more cleanly. The whole architecture is far less of a heap of historical bodges piled one upon the other. So what you as an end user will see are the end products of that.

The few things that will directly impact you will be:

• The simpler power-on self-test sequence.
• The support for avoiding the 2TiB disc size limitation.
• The extra pre-boot recovery and servicing mechanisms, such as the EFI Shell (on machines that have it).

You won't directly see an impact from the fact that operating systems developers no longer have do deal with real mode anywhere, in contrast, or from the fact that systems programs such as bootstrap loaders can be written entirely without using assembly language, or from the fact that the firmware supplies graphics routines and support for reading the disc in chunks greater than 64KiB at a time. Those, and several other advantages, only affect you indirectly. You'll only see the effects of them, through the lens of the impact that they have on systems softwares.

Further reading

• Jonathan de Boyne Pollard (2011). The gen on the 2TiB disc size limit. Frequently Given Answers.
• Jonathan de Boyne Pollard (2006,2011). The EFI boot process.. Frequently Given Answers.
• Microsoft corporation (2009-09-14). UEFI and Windows. Windows Dev Centre.
• Bhaskar Mukkamala (2010-08-06). UEFI Aware OS Deployment on Dell PowerEdge Servers using Unified Server Configurator. Dell corporation.
• Brooke Crothers (2010-10-05). Getting a Windows PC to boot in under 10 seconds. c|net News.

The Wikipedia article on UEFI lists advantages of UEFI.

I don't think you would gain much from using it unless you want to boot a drive that is larger than 2TiB (but then you would be pretty much forced to use it anyway).