This guide is obsolete. An up to date guide which covers downloading Windows 7 Installation Media, slipstreaming updates and drivers, creating a Bootable USB and Clean Installing with OEM System Locked Preinstallation is available here:
This will perform a clean installation of Windows 7 64 Bit removing all data on your system's drives.
If you have not backed up your data and you have came to this guide because your system cannot boot. Please run the preboot diagnostics.
And attempt data recovery to an external hard drive using Fedora before proceeding:
The UEFI BIOS and GPT partition scheme should be used where possible with Windows 7 64 Bit. You may or may not have these technologies depending on the age of your system. For reference:
- OptiPlex 390/790 – 2011 (2nd generation Sandy Bridge) UEFI BIOS – No Secure Boot, there is no option for Legacy ROMs as these are always Enabled
- OptiPlex 3010/7010 – 2012 (3rd generation Ivy Bridge) UEFI BIOS with Secure Boot (only with the latest UEFI BIOS Update)
- OptiPlex 7020 – 2014 (4th generation Intel Haswell) UEFI BIOS with Secure Boot
- OptiPlex 7040 – 2015 (6th generation Intel Skylake) UEFI BIOS with Secure Boot
This guide focuses on a UEFI BIOS, if you have an even older Dell System than 2011, ignore any mention of the words UEFI, Legacy ROMs and Secure Boot as the technologies are not available in your system. Such systems have a Legacy BIOS (non-UEFI) BIOS. Installation instructions are otherwise identical however the installation media for them needs to be made using the MBR partition scheme and NTFS file format opposed to the GPT partition scheme and FAT32 format.
On a Dell system press [F2] to enter the UEFI BIOS setup, I'll demonstrate using the newest hardware supported to run Windows 7 64 Bit – the OptiPlex 7040:
Windows 7 64 Bit does not support Secure Boot, it must be Disabled in the UEFI BIOS setup for Windows 7 64 Bit Installation. Look for a tab called Secure Boot, expand it, select Secure Boot Enable and change the setting to Disabled. Select OK at any warning dialog box:
Legacy Option ROMs must be enabled for Windows 7 64 Bit. Go to the general tab and select Advanced Boot Options, ensure Enable Legacy Option ROMs are Enabled. You should leave Enable Attempt Legacy Boot unchecked:
Next go to Boot Sequence and ensure the Boot List Option is set to UEFI:
It is also worth looking at your Drives here – in my case I have one 128 GB SSD drive that is M.2, others may have a HDD and a low capacity 32-64 GB SSD Cache Drive:
For a single Drive I can use RAID On or AHCI. If you have a small capacity SSD and a large HDD you would need to select RAID On (sometimes called Intel Smart Response Technology):
Now exit the UEFI BIOS setup to save the changes:
Using updated installation media will reduce the hassles of Windows 7 Installation Failure due to lack of native driver support for systems with a UEFI BIOS and greatly reduce the installation time due to the inefficiencies of Windows Update. Follow my instructions to Download Dell Windows 7 Pro ISO (Media Refresh January 2016) from Dell and Make a Bootable USB.
Power Down your Dell an Insert your Windows 7 Installation USB and make sure no other USB Devices are connected except for the Keyboard and Mouse. If using a Dell OptiPlex model (or other Desktop) I recommend using the back USB Ports as these are directly on the System Board and Avoiding the Front Ones for Windows 7 Installation.
Hold [F12] while powering up your computer:
You will now enter the UEFI BIOS Boot Menu:
Notice that it says to the top that the Boot Mode is set to UEFI and Secure Boot is OFF. Press [↓] until you get to your USB Flash Drive (in my case it is a Sandisc Cruzer Glide 16 GB), ignore any listings sunder Legacy Boot.
Some systems may tell you to press any key to continue Booting from USB, if they do press the space bar.
You will get a black screen that says "Windows is Loading Files."
Then one that says Starting Windows.
You will then be prompted for your language, time and currency format and keyboard settings, amend these as desired. If you use an English .iso it'll be set by default to English (US), I'm going to change to English (UK):
Select Install Now.
You will get a Setup is Starting Screen:
You may get a file asking you what Edition of Windows you wish to install. This depends if the installation media has an EI.cfg file – the EIF.cfg file is a text file which automatically selects the option at this screen. In my case I am going to install Windows 7 Professional using Downgrade Rights from Windows 10 Pro OEM on a Dell OptiPlex 7040: