I'll answer the question, but fyi although Windows 7 can boot in UEFI mode (sort of, see below), it does not take advantage of any UEFI benefits.  The ONLY reasons you should install Windows 7 in UEFI mode are if you a) want to install it on a disk larger than 2TB and/or b) want to install Windows 7 and some OTHER operating system that uses UEFI mode on the same disk.  If neither of those applies to you, then you may as well install it in Legacy mode.

But if you're determined to use UEFI, even when Windows 7 is set up in UEFI mode, it still has some Legacy BIOS dependencies.  If you try to boot it on a system that is pure UEFI, it will blue screen.  To make it work, you need to disable Secure Boot and then also ENABLE Legacy Option ROMs.  But despite doing that, when you choose to boot from your installation media under the F12 one-time boot menu, you have to select the option for your device under the UEFI section, NOT the Legacy section.  Legacy Option ROMs is normally enabled to allow Legacy booting, but in this case it just allows Windows 7's legacy dependencies to be used even when it boots in UEFI.  Anyhow, as long as you boot your installation media in UEFI mode, Windows Setup will install the OS onto your disk in UEFI mode.

---

@EngiProg wrote:

Thanks jphughan:

I thought I had to change some setting(s) in BIOS to Boot for UEFI to make GPT disk

 

---

The BIOS changes you have to make are to put your system into UEFI mode rather than Legacy, and then enable Legacy Option ROMs (which requires you to disable Secure Boot).  That configuration allows your system to boot in UEFI mode even for Windows 7.  In terms of a GPT disk, that's handled by Windows Setup.  Again, as long as you boot your Windows installation media in UEFI mode, it will automatically install the OS onto your hard drive in UEFI mode, which includes setting up the disk as GPT.  If you already have data on that disk, then at the step where you select where to install Windows, delete all existing partitions on that disk until the entire disk shows up as unallocated space, then select that.  Windows will handle the rest.

Thanks jphughan:

I thought I had to change some setting(s) in BIOS to Boot for UEFI to make GPT disk

@EngiProg, one other bit of advice for you. Since you're performing a clean install of Windows 7 in 2019, you'll want to manually download a few other updates beforehand rather than planning to just use Windows Update when it gets installed.  You will save a huge amount of time.  The reason is that Windows 7 SP1 is very old now, so if you don’t do this, you could spend many hours installing hundreds of updates over several reboots.  In fact, the version of Windows Update included in original SP1 has an issue that causes it to sometimes take hours to even figure out what needs to be downloaded, before it actually downloads anything. It simply wasn't designed for the size of the update catalog that exists today.

Fortunately, manually downloading the updates below will avoid that. Just Google the KB numbers to find the download links. This assumes you're start from SP1, otherwise download and install SP1 first, then install these updates in this order:

- KB3020369: April 2015 Servicing Stack Update (required to install subsequent updates)

- KB3125574: Windows 7 Convenience Update (takes you from SP1's February 2011 state all the way to April 2016 in one big package rather than hundreds of individual updates)

- KB3172605: July 2016 Update Rollup (includes the fix for very long Windows Update scan times, so after installing this, you may still have a few dozen updates, but at least you won't be waiting potentially hours for them to even start downloading).

Fyi though, Microsoft will stop providing security updates for Windows 7 in January 2020, and if Windows XP's retirement is any indication, browser vendors will stop providing updates on Windows 7 shortly afterward, so if you plan to keep this system longer than that, you might want to think about upgrading to Windows 10 sooner rather than later.

Hello jphughan:

Thanks for advising, whenever I do a clean install, I always download the latest build, which I believe reduces massive updates

I’m unsure if I could get all the latest drivers for this laptop (Latitude E6420) for Windows 10 64-bit (knowing most of the W7 onward drivers work with W10), could you please provide URL for latest W10 Pro 64-bit for this laptop

Thanking you in advance

---

@EngiProg wrote:

Hello jphughan:

Thanks for advising, whenever I do a clean install, I always download the latest build, which I believe reduces massive updates

I’m unsure if I could get all the latest drivers for this laptop (Latitude E6420) for Windows 10 64-bit (knowing most of the W7 onward drivers work with W10), could you please provide URL for latest W10 Pro 64-bit for this laptop

Thanking you in advance

---

Microsoft hasn't provided updated Windows 7 media since SP1, so downloading it now will not give you any additional updates -- which is why I made the suggestion above.  Dell doesn't offer Windows 10 drivers for that system, but it does offer Windows 8 drivers, so it's likely that Windows Update would provide the necessary Windows 10 drivers.  If you're missing any low-priority drivers after that, it's very likely that the Windows 8 drivers will work.

Hi jphughan:

Thanks on the heads-up on media update of W7 download from MS

I’d go for W10 Pro 64-bit as long as following are available:

1. Audio
2. Network (LAN & WiFi)
3. Video

Anyone who experienced may please chime

Thank you

---

@EngiProg wrote:

Hi jphughan:

Thanks on the heads-up on media update of W7 download from MS

I’d go for W10 Pro 64-bit as long as following are available:

1. Audio
2. Network (LAN & WiFi)
3. Video

Anyone who experienced may please chime

Thank you

 

---

Those will definitely be available because that system uses Intel and Realtek for those items, and both Intel and Realtek provide drivers through Windows Update.  In fact given the age of that system, you'll probably find that Windows 10 has support for those things out of the box.

UEFI is only windows 8 or 10.

WINDOWS 7 SUPPORTS GPT but does not support UEFI SECURE BOOT.

E6420   E6420ATG  SYSTEMS are windows 8 MAX

as far as released drivers.

https://www.dell.com/support/article/us/en/19/how13996/latitude-e6420-windows-8-driver-cab?lang=en

https://www.dell.com/support/article/us/en/19/how13793/latitude-e6420-windows-7-driver-cab?lang=en

E6420XFR
https://www.dell.com/support/article/us/en/19/sln312677/latitude-e6420xfr-windows-7-driver-cab?lang=en

GPT is a partition type that goes back to XP.

You cannot make a GPT partition boot in XP.

Any Partition larger than 2TB requires 64 bit windows OS.

Partitions larger than 2TB require INTEL RST Drivers version 10.1.0.1008 or Higher.

Windows 8 and 10 drivers are not available for older models but that does not mean you cannot use VISTA or  Windows 7  WDDM 1.0 drivers in windows 8 or 10.

Single Driver packages for a specific series are available.

https://www.dell.com/support/article/us/en/19/sln312414/dell-command-deploy-driver-packs-for-enterprise-client-os-deployment?lang=en

Not Supported is not the same as not working with windows 8 or 10.

Hello All!

I’m sorry to be little late, I have latest BIOS A25 installed, I’ve two issues at the moment which I’d like to resolve before proceeding for fresh W10 installation

1. Device Manager is showing my system as E6249 – don’t know why?
   It should be E6240 as on boot splash screen
   
   
   
2. Bluetooth installation failed – can someone provide solution reviewing log?
   Need help on this please
   
   

Log First attempt

[03/15/19 20:17:53] Update Package Execution Started
[03/15/19 20:17:53] Original command line: "D:\Drivers\Dell 6420\Driver\Network\Bluetooth\Network_Driver_1G1GX_WN32_6.3_A07.EXE"
[03/15/19 20:17:53] DUP Framework EXE Version: 3.0.92.1
[03/15/19 20:17:53] DUP Release: 1G1GXA00-00
[03/15/19 20:17:53] Intializing framework...
[03/15/19 20:17:55]
[03/15/19 20:18:19] User Command: attended
[03/15/19 20:18:19] DUP Capabilities Value: 8388607 (0x7FFFFF)
[03/15/19 20:18:19] DUP Vendor Software Version: 6.3
[03/15/19 20:18:19] Local System/Model Compatible with this Package? Yes
[03/15/19 20:18:19] Local System OS Version: 6.1.1.0
[03/15/19 20:18:19] OS Compatible with this Package? Yes
[03/15/19 20:18:19] Local System OS Language: EN
[03/15/19 20:18:19] Language Compatible with this Package? Yes
[03/15/19 20:18:19] (DupAPI::ExtractPayloadTo): *** Extraction Error: 9
[03/15/19 20:18:19]
[03/15/19 20:18:19] Name of Exit Code: ERROR
[03/15/19 20:18:19] Exit Code set to: 1 (0x1)
[03/15/19 20:18:19] Result: FAILURE
[03/15/19 20:18:30] Open file: C:\Users\Dell\AppData\Local\Dell\UpdatePackage\Log\Network_Driver_1G1GX_WN32_6.3_A07.txt

Log Second attempt

[03/15/19 20:17:53] Update Package Execution Started
[03/15/19 20:17:53] Original command line: "D:\Drivers\Dell 6420\Driver\Network\Bluetooth\Network_Driver_1G1GX_WN32_6.3_A07.EXE"
[03/15/19 20:17:53] DUP Framework EXE Version: 3.0.92.1
[03/15/19 20:17:53] DUP Release: 1G1GXA00-00
[03/15/19 20:17:53] Intializing framework...
[03/15/19 20:17:55]
[03/15/19 20:18:19] User Command: attended
[03/15/19 20:18:19] DUP Capabilities Value: 8388607 (0x7FFFFF)
[03/15/19 20:18:19] DUP Vendor Software Version: 6.3
[03/15/19 20:18:19] Local System/Model Compatible with this Package? Yes
[03/15/19 20:18:19] Local System OS Version: 6.1.1.0
[03/15/19 20:18:19] OS Compatible with this Package? Yes
[03/15/19 20:18:19] Local System OS Language: EN
[03/15/19 20:18:19] Language Compatible with this Package? Yes
[03/15/19 20:18:19] (DupAPI::ExtractPayloadTo): *** Extraction Error: 9
[03/15/19 20:18:19]
[03/15/19 20:18:19] Name of Exit Code: ERROR
[03/15/19 20:18:19] Exit Code set to: 1 (0x1)
[03/15/19 20:18:19] Result: FAILURE
[03/15/19 20:18:30] Open file: C:\Users\Dell\AppData\Local\Dell\UpdatePackage\Log\Network_Driver_1G1GX_WN32_6.3_A07.txt
[03/15/19 21:01:45] Name of Exit Code: ERROR
[03/15/19 21:01:45] Execution terminated at date-time 03/15/19 21:01:45
[03/15/19 21:01:45] ######

਍਍[03/15/19 23:03:49] Update Package Execution Started
[03/15/19 23:03:50] Original command line: "D:\Drivers\Dell 6420\Driver\Network\Bluetooth\Network_Driver_1G1GX_WN32_6.3_A07.EXE"
[03/15/19 23:03:50] DUP Framework EXE Version: 3.0.92.1
[03/15/19 23:03:50] DUP Release: 1G1GXA00-00
[03/15/19 23:03:50] Intializing framework...
[03/15/19 23:03:57]
[03/15/19 23:04:01] User Command: attended
[03/15/19 23:04:01] DUP Capabilities Value: 8388607 (0x7FFFFF)
[03/15/19 23:04:01] DUP Vendor Software Version: 6.3
[03/15/19 23:04:01] Local System/Model Compatible with this Package? Yes
[03/15/19 23:04:01] Local System OS Version: 6.1.1.0
[03/15/19 23:04:01] OS Compatible with this Package? Yes
[03/15/19 23:04:01] Local System OS Language: EN
[03/15/19 23:04:01] Language Compatible with this Package? Yes
[03/15/19 23:04:02] (DupAPI::ExtractPayloadTo): *** Extraction Error: 9
[03/15/19 23:04:02] Identified Behavior : attended
[03/15/19 23:04:02]
[03/15/19 23:04:02]
[03/15/19 23:04:02] Name of Exit Code: ERROR
[03/15/19 23:04:02] Exit Code set to: 1 (0x1)
[03/15/19 23:04:02] Result: FAILURE
[03/15/19 23:04:07] Name of Exit Code: ERROR
[03/15/19 23:04:07] Execution terminated at date-time 03/15/19 23:04:07
[03/15/19 23:04:07] ######

਍਍[03/16/19 20:02:38] Update Package Execution Started
[03/16/19 20:02:38] Original command line: "D:\Drivers\Dell 6420\Driver\Network\Bluetooth\Network_Driver_1G1GX_WN32_6.3_A07.EXE"
[03/16/19 20:02:38] DUP Framework EXE Version: 3.0.92.1
[03/16/19 20:02:38] DUP Release: 1G1GXA00-00
[03/16/19 20:02:38] Intializing framework...
[03/16/19 20:02:38]
[03/16/19 20:03:21] User Command: attended
[03/16/19 20:03:21] DUP Capabilities Value: 8388607 (0x7FFFFF)
[03/16/19 20:03:21] DUP Vendor Software Version: 6.3
[03/16/19 20:03:21] Local System/Model Compatible with this Package? Yes
[03/16/19 20:03:21] Local System OS Version: 6.1.1.0
[03/16/19 20:03:21] OS Compatible with this Package? Yes
[03/16/19 20:03:21] Local System OS Language: EN
[03/16/19 20:03:21] Language Compatible with this Package? Yes
[03/16/19 20:03:21] (DupAPI::ExtractPayloadTo): *** Extraction Error: 9
[03/16/19 20:03:21] Identified Behavior : attended
[03/16/19 20:03:22]
[03/16/19 20:03:22] Name of Exit Code: ERROR
[03/16/19 20:03:22] Exit Code set to: 1 (0x1)
[03/16/19 20:03:22] Result: FAILURE
[03/16/19 20:03:59] Open file: C:\Users\Dell\AppData\Local\Dell\UpdatePackage\Log\Network_Driver_1G1GX_WN32_6.3_A07.txt

Thanks in advance