This guide is obsolete.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:

Tutorial Video

Written Guide

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.

  • Dell F12 UEFI Preboot Diagnostics
    • Dell Systems Older than 2010 – Legacy Preboot Diagnostics (Bootable USB)
  • Lenovo F10 UEFI Preboot Diagnostics

And attempt data recovery to an external hard drive using Fedora before proceeding:

  • Data Recovery Using Fedora

Part 1: Determining whether your System Supports UEFI and Secure Boot

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:

Select Apply:

Press OK:

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:

Part 2: Preparing Up to Date Installation Media

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.

Part 3: Booting from 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.

Part 4: Early Installation

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:

Read the license, check to select and then select Next.

Next select Custom (Advanced).

Part 5: Loading SATA Drivers and Deleting Partitions

Warning: This step will result in data loss of internal drives.

If you are clean installing Windows due to a Boot Problem and cannot backup your data as Windows cannot boot the follow my guide Data Recovery using Fedora which uses a Bootable Fedora Live Linux USB which can access the HDD/SSD in many cases when Windows cannot.

If the Windows 7 installation media can see your SSD/HDD/HSSD on the next screen then you do not need to load a SATA preinstallation driver as it's incorporated. This should be the case for the Dell Skylake Reinstallation .isos which have support for up to 6th generation Intel Skylake systems.

Loading SATA Drivers

Most UEFI systems have hardware substantially newer than Microsoft's Windows 7 Installation Media from 2010 and as a consequence Windows 7 does not have the SATA drivers required for your Storage Controller. It cannot read your SSD/HDD/HSSD.

If no drives are listed on the "Where do you want to install Windows?" screen then you must select Load Driver and select the SATA drivers from a USB stick. The SATA drivers essentially allow Windows to recognise the hard drive controller on the motherboard and thus allow Windows to view the drive letting you proceed with the install.

Note the error message here says:

"No Drives were Found. Click Load Driver to Provide a Mass Storage Driver for Installation".

Quite often other error messages show such as

"A media driver your computer needs is missing"

"A required CD/DVD drive device driver is missing"

These normally mean your installation media is corrupt and are not because you need to load a driver. "A required CD/DVD drive device driver is missing" quite often shows on Desktops when the Front USB Ports are used, move your Bootable USB to the back USB Ports instead and restart the computer.

If instead you have a previous version of Windows on your drives screen may instead look like this.

Warning 2: This step will result in data loss of internal drives.

You can perform a Low Level Format using the Windows Installation Media by Deleting all the partitions on the drive. You should do this if:

  • You are clean installing the latest version of Windows 10 on your PC.
  • You are sure your old version of Windows wasn't infected with malicious software.
  • You are keeping your computer…

You should instead quit Windows Installation and perform a Secure Wipe  using Dell Data Wipe or Parted Magic if:

  • You are clean installing the latest version of Windows 10 due to a malicious software.
  • You have bought your computer second hand (and are not sure what the last user has had on the PC).
  • You are planning selling your computer on (and don't want personal data passed on).

To perform the Low Level Format using the Windows Installation Media select every partition on Drive 0 (or the desired Drive you wish to install Windows if you have a system with a multiple drive configuration) and systematically delete any partition.

Delete all Partitions including Recovery Partitions , these are for old obsolete versions of Windows and no longer required.

If multiple drives show you may have a SSD and a HDD.

If your SSD is >128 GB install Windows 7 on your SSD as it'll result in optimal performance.

If it is 32-64 GB it should be a cache drive. Remove all partitions on it and on the HDD. Then install on the HDD. The SATA Operation needs to be in RAID. Notes on setting up Intel Rapid Storage Technology to use the SSD as a cache drive will be given later.

Part 6: Middle of Installation

You will then a screen telling you the progress of the install and Windows will restart once:

Type in your "username", by default the PC name will be "username-PC" but you can change this as desired.

Next type in your password, retype it and leave yourself a hint.

Alternatively just select next (to have no password – not recommended but optional). Personally for convenience I tend to leave the password blank and add one after the installation of Windows 7, drivers and updates as you will be prompted to restart your computer several times.

Part 7: The Product Key

You should only input a Product Key at this stage if your License is Retail Full, otherwise select Skip for OEM Licenses and Retail Upgrade Licenses. Note this screen will not show at all if using Dell Windows 7 Reinstallation Media. Installation without a Product Key will give a 30 Day Trial (we only need about 30 mins of this trial before we go ahead and activate Windows).

Part 8: End of Installation

You will then be asked about Windows Update settings its generally best to go with recommended.

Then select your time and date settings.

The next screen should be about connecting to the internet and/or connecting to a wireless network. In most cases Windows 7 won't have the driver inbuilt for a UEFI system and this screen will not show. The setup will Finalise and restart taking you to the Windows Desktop.

Part 9: Install the Latest Security Updates

If you've followed my guide to make Slipstreamed Windows 7 Installation Media, you will only need to install Microsoft .Net Framework and Microsoft Security Essentials. You may need to install the latest Security Rollup.

If you've used the Dell Windows 7 Pro  2016 Skylake Reinstallation ISO (and are installing the Pro Edition) without Slipstreaming additional updates. You will need KB3020369, KB3125574 (restart), the latest Security Rollup, Microsoft .Net Framework and Microsoft Security Essentials.

If you've used the Dell Windows 7 Pro 2016 Skylake Reinstallation ISO (and are installing a Non-Pro Edition) without Slipstreaming additional updates. You will need KB3020369, KB3125574 (restart), KB2639308, KB2670838, KB2729094, KB2834140 (restart) then IE11-Windows6.1and the latest security rollup. After these are installed, install the Microsoft .Net Framework.

If you've used the Microsoft Windows 7 Pro SP1 2011 ISO (and are installing a Non-Pro Edition) without Slipstreaming additional updates. You will need KB3020369, KB3125574 (restart), KB2639308, KB2670838, KB2729094, KB2834140 (restart) then IE11-Windows6.1 and the convenience rollup. After these are installed, install the Microsoft .Net Framework.

See here for Windows 7 Standalone Updates.

Part 10: Activation

If you have used OEM Reinstallation Media on an OEM System e.g. the Dell Windows 7 Professional Reinstallation ISO or DVD on an eligible Dell System, Windows 7 should be activated offline automatically using OEM System Locked Preinstallation.

If you have used Retail Installation Media with a Full Retail Product Key you should automatically activate Windows 7 when online.

If you have used Retail Installation Media on an OEM System e.g. the Microsoft Windows 7 Retail ISO or DVD on an eligible Dell, HP or Lenovo System, you will need to manually apply OEM System Locked Preinstallation.

If you have used Retail Installation Media with a Retail Upgrade Only Product Key then you may have activation issues after performing a clean installation. You should activate by the Command Prompt instead.

Part 11: System Drivers

You should now look at installing your system drivers starting with the Dell System Software (if applicable for your system) and the Chipset drivers. See Driver Installation Order for more details.

If using a SSD Cache Drive be sure to set it up after driver installation following the instructions here.

Part 12: Security

You may have installed Microsoft Security Essentials for Windows 7 above to give your system base system security. However Windows 7 isn't as Secure as Windows 10 and you may want to install another security product then I recommend Malwarebytes' AntiMalware. There is a free version which only does an on demand scan or a paid version which does Realtime Protection. Below is an affiliate link:

Malwarebytes for Home | Anti-Malware Premium | Free Trial Download