How to dual boot Windows 10 and Windows 7 after you upgraded to Windows 10 or have purchased a new Windows 10 PC
You have upgraded or performed a clean install of Windows 10 and find that you need Windows 7 for some of your applications. Here is how you can reinstall Windows 7 (or 8.1) and still keep Windows 10.
Instructions are also provided on how to uninstall Windows 7 or 8.1 and keep Windows 10 if you no longer plan to use Windows 8.1 or 7.
6 Things you need to know before your start :
1) Your PC may refuse to boot and or unexpected PC crashes could damage or even delete your files, so you should create an Image backup your Windows 10 installation before you proceed to install Windows 7.
2) If you purchased a new computer with Windows 10 preinstalled then check your manufacture’s support web site to see if there are Windows 7 (or 8.1) device drivers available. The lack of device drivers is a good indication that your new computer is not Windows 7 compatible.
3) If you upgraded from Windows 7 or 8.1 to Windows 10 then you cannot use your existing product key to re-install Windows 7 or 8.1 as it was the basis for your free upgrade to Windows 10. Therefore you must either have another unused product key and installation media or purchase another copy (OEM or Retail) version of Windows 7 or 8.1, note that anyone who offers to sell you just a product key without any installation media may be a scammer.
4) Create an Image Backup of your existing Windows 10 installation before you start the process of installing Windows 7 or 8.1
5) You will need to “Shrink” the existing Windows 10 partition to create space (another partition) for Windows 7 or 8.1.
6) Once Windows 7 is installed you will need to re-install your applications that are not compatible with Windows 10 so locate the application(s) installation media and associated product key(s) that need to be re-installed.
Understanding Disk Drive Partitions and what needs to be backed up:
There are numerous partitions and various arrangements of the partitions on your disk drive. If you have a standard BIOS (non UEFI) based computer, you may only see as little as a “System” partition, “Windows” Partition and possibly separate “Recovery” and “Utility” partitions. UEFI based system are more complex so I’ve included some samples listed below.
Each computer manufacture may have their own partition schemes with preinstalled versions of Windows. Systems upgraded from Windows 7 have yet another partition layout and finally to home built systems and the user’s own choice of partitions.
TechNet has a good article that covers a number of BIOS and UEFI partition arrangements:
For UEFI/GPT partition arrangements see:
For this Wiki article I will be using a UEFI based drive partition arrangements with respect to creating an Image Backup and installing Windows 7.
Image Backup concepts:
All backups will be made from the Windows 10 environment and backup restoration / drive recovery will be made from a bootable recovery disk.
One such backup method would be an image of the entire hard drive before you start preparing the drive prior to installing Windows 7. This is the backup method I will be using.
Note: The backup software should be installed in and the "Drive Image" created from the Windows 10 environment before you make any partition changes and or installing Windows 7. Each of the Image Backup software applications mentioned will backup and restore (restore when using their “Rescue / Recovery DVD”) your Windows 10 and Windows 7 / 8.1 partitions or the entire disk drive.
Image Backup Software:
Please note that backup software like all software are subject to periodic updates or totally new releases. The versions listed below where current at the time of this publication. Most vendors offer a “Free” version or Trial edition.
EaseUS Todo Backup Home: http://www.todo-backup.com/home/home-backup.htm
Macrium Reflect: http://www.macrium.com/reflectfree.aspx
Image Backup Strategy:
1) Create the bootable “Recovery” media. Some of the backup utilities provide a choice of creating either a standard / basic bootable media or a WinPE based bootable media. The WinPE media is more compatible with various hardware and USB ports, I usually create both types of recovery media and if one doesn’t recognize you external USB backup drive the WinPE media will.
2) Next an “Initial Baseline” image backup of the entire drive will be created.
3) A second pre-Windows 7 baseline image backup of the entire drive will be created after you have shrunk the Windows 10 (C:) partition is to create space for use when installing Windows 7 or 8.1, this second baseline will be used as a starting point prior to installing Windows 7 or 8.1.
4) A third backup of your dual boot PC will be created after you have installed Windows 7 / 8.1 and associated device drivers but before you have installed the 150 or more Windows Updates.
5) After the backup has completed then install the updates in small groups of 10 or 20 at a time, saving the .NET Framework and IE11 updates for last. If something should go wrong when installing the updates you can start over by restoring just the Windows 7 or 8.1 partition from your previous backup created in step #4.
6) Once all your updates have been installed verify Windows 7 /8.1 is fully functional and then create another backup.
7) Install your applications and you guessed it, create another backup.
For steps 5, 6 and 7 you can save time and external USB drive disk space by just performing a backup of just the Windows 7 or 8.1 partition or if you like a backup of the whole drive. Either type of backup will allow you to restore a partition.
Initial Baseline Image Backup:
Prior to making any changes to your computer’s drive you need to establish a baseline backup of the entire drive in case you need to restore Windows 10 to its current state (containing all your data files and applications) for whatever reason after installing Windows 10 or you are no longer able to boot to Windows.
The screenshots below shows a typical 1TB drive with 3 partitions when using the Disk Management utility.
The image backups you will create over time, will eliminate the need to use the recovery partition to reinstall Windows 10, and preserves your Apps and data files. Think of these backups as your safety net should you have problems with a particular Windows Update or software application update.
My personal style of where and how to store the Image Backup file includes the use of an external USB drive and a destination folder name (created prior to launching the image backup software). The folder name should have some meaning (Example: Windows10_Initial_Baseline_Backup). Inside this folder I also create a small Notepad Readme.txt file that includes notes about why and when the backup was created.
The time to complete the backup is dependent on the image compression level, amount of data / used drive space your Windows 10 partition contains and to some extent the size of your recovery partition. You can choose Medium or High compression (these option vary depending on what vendor’s Image Backup software you are using) as it provides a good balance between the size of the image backup file on the USB drive and the time to complete the backup. Higher compression levels usually do not save all that much space and can add significant time to the backup completion time.
After your baseline backup has completed, the next step is to shrink the existing Windows 10 (C:) partition to make room for an additional partition to be used when installing Windows 7 or 8.1.
How to create space for a Windows 7 partition on your Windows 10 disk drive:
The 1TB hard drive I’m using for this article contains 3 partitions. The first is the 450MB Recovery partition, the second a 100MB EFI System partition and the third and last partition is the Windows 10 partition. We need to shrink (reduce the size) of the Windows 10 partition to create space for the Windows 7 partition.
Note: Sometimes the use of a 3rd party utility such as Partition Wizard Home Edition: http://www.partitionwizard.com/free-partition-manager.html
or EASEUS Partition Master Home Edition: http://www.partition-tool.com/personal.htm
may be required.
A) The location of the Master File Table (MFT) or other locked files may limit the amount of space / value in MB that you can enter in step #3.
B) You already have 4 “Primary” partitions, therefore you need to convert to an “Extended” partition with a “Logical” drive. Another option is with a drive that is initialized with a Master Boot Record (MBR) to convert it to a GPT (GUID Partition Table). GPT allows for more than 4 Primary partitions.
To create the space needed for Windows 7 we will use Windows 10’s Disk Management to “Shrink” the Windows 10 partition which results in “unallocated” space for use when installing Windows 7.
1. Open Disk Management and right click on the Windows 10 partition.
2. Select the “Shrink Volume…” option.
3. I’m going to create a 400GB partition for Windows 7 so I’ll enter the value 409600.
(100GB = 102400, 200GB = 204800, 300GB = 307200, 400GB = 409600)
Note that the “Size of available shrink space in MB” is the maximum amount the Windows 10 partition can be reduced by.
4. Click on the “Shrink” button after you enter the appropriate value for your hard drive. When the shrink operation has completed you should see an area of “Unallocated” space, 400GB in the screenshot shown below.
At this point you can either choose to pre-format the unallocated space (see step #5) in advance of installing Windows 7 or leave the space “Unallocated” and format during the installation process. If you want to leave the space as “Unallocated” then skip to step #6.
5) Formatting the unallocated space:
Right click on the “Unallocated” space and choose the ‘New Simple Volume…’ option.
Give the Volume label an easy to recognize name as this will make it easier to spot which partition you want to install Windows 7 on during the installation process.
Note: For users who have an SSD drive be sure to use the default “Perform a quick format” option.
Hard Disk Drive user can perform a “Full” format if desired by removing the check mark as shown below.
6) At this point it’s time to create your second baseline backup.
It does not matter if you choose to format the new partition or leave it as unallocated space you should create a new backup to a new and separate folder on your external USB drive, the new folder will insure you still have your original “baseline” image backup file separate and protected from a possible over write when creating the second baseline backup.
This second backup is the backup you can use to “restore” your drive back to a pre Windows 7 state should the Windows 7 installation fail for whatever reason and you need to try installing Windows 7 again.
Installing Windows 7:
First you need to verify and if necessary change the boot order in the UEFI settings so that your PC will boot from the DVD drive (or USB device if you created a bootable USB Flash drive). You can do this by making the DVD drive / USB device the first device listed in the boot order and the hard (or SSD) drive your second device, exit as save the changes.
User who have a standard BIOS (usually found on most pre Windows 8 systems) from Windows 10, insert the Windows 7 DVD. If the AutoPlay window opens, do nothing except to close it; now reboot the computer.
For computers that are UEFI based (Does not have a standard BIOS found earlier / pre Windows 8 based computers) you will need to select the appropriate boot device.
If you see the “press any key” message displayed.
1) Press the keyboard’s space bar several times and wait for the “Windows” Logo / splash screen to be replaced (this may take some time) by the Windows 7 Language, Time and currency and the Keyboard setup screen. Make any changes (if needed) and click the ‘Next’ button.
2) Click on the “Install now” option located in the center of the screen.
3) Read and accept the License terms and click ‘Next’.
4) Which type of installation do you want?
Choose the “Custom: install Windows only (Advanced)” option.
5) Where do you want to install Windows?
Select / highlight the partition named (Win7 or the name you assigned when formatting) or the “Unallocated” space you created by shrinking the Windows 10 partition.
Click ‘Next’ to continue.
If you see the warning message below click ‘OK’ to proceed. This message is the result of installing an older version of Windows after Windows 10 has already been installed.
6) Windows 7 will now start a series of installation steps, followed by a restart / reboot of your PC.
Copying Windows files.
Getting files ready for installation
Installing updates (Automatic reboot, no action required on your part)
Windows will now restart
From this point on, if you see a prompt like the two shown below, take no action, don’t touch the keyboard.
By default the Windows 7 will continue the installation process, just wait for the timer to expire. You may have noticed the graphical (GUI) boot menu is replaced by the text based menu. This is a result of Windows 7 being installed last (After Windows 10).
7) After Windows 7 has finished the installation process:
You should boot to Windows 7 you will need to install your Device Drivers for your computer’s (HP, Dell, Acer, Toshiba, Etc.) or if built your own system the drivers for motherboard manufacture’s make and model , starting with the Chipset driver, LAN, USB, Audio, Etc .
Install Windows Updates in small batches of 20 at a time, saving the .NET Framework updates for last. It is a time consuming task, but you are less likely to have problems. I’ve noticed that some updates fail to install, but when trying a second time they install without any issues.
Install any applications that need to run in a Windows 7 environment and verify they function properly.
That’s it; you have completed the Windows 10 / Windows 7 dual boot installation.
Final Image Backup:
Before you go exploring it’s time to make that final image backup. So reboot the computer, click on the Windows 10 boot menu option, then launch your backup software and create a backup of the entire drive.
After completing the image backup your USB drive should have 3 folders and look similar to that shown below.
Note: Should you need to restore Windows 7 or the Windows 10 you can just select the partition that you want to restore, no need to restore the entire drive.
If you are using Windows 7 for most of your work and just exploring Windows 10 then you should consider creating a “Scheduled” daily backup of the Windows 7 partition, or you can include both Windows 7 and 10 partitions if you like and have the available space on your external USB drive. Pick a time when you know the PC will be on but you’re not using it, Dinner time for example.
Uninstalling Windows 8.1 or Windows 7
If you decide you no longer need Windows 8.1 or Windows 7 but still plan to continue using Windows 10 here how to remove your earlier version of Windows from the boot menu and delete Windows 7 or 8.1
It is recommended that you make an Image Backup before you make any changes. Should anything go wrong you can always restore the image and try again.
1) Start Windows 10 and in the search box type: msconfig and tap the 'Enter' key. Then click on the 'Boot' tab.
2) Select / Highlight the Windows 7 or 8.1 entry and click on the 'Delete' button.
3) Click on the 'Apply' button.
4) Click 'OK' to save your changes. Windows 10 will now be the default and only version of Windows that boots and loads.
5) Click either option.
6) After you reboot Windows 10 open Disk Management and delete or format the Windows 7 / 8.1 partition. You can choose to use the partition for whatever purpose you like or delete it and reclaim / merge the space into your existing Windows 10 partition by using the 'Extend' partition option.
Please note that your partition arrangements and sizes may vary from the example shown below.