Installing Windows 7 (dual-boot) after having installed Windows 8

Question

I have installed Windows 8 Pro x64 over my previous Windows 7 installation. However, I need to re-install Windows 7 on a second partition, in other words, with dual-boot functioning.

When I boot the USB, containing the installation files, windows 7 starts installing. When prompted what partition I want to use, I select a 40GB, NTFS-formatted, partition. Normally, here I should be able to click on the button "Next", however, the button is disabled and when I click on the link "Windows cannot be installed on Disk 0, partition 4", a Messagebox prompts saying:

Windows cannot be installed to this disk the partition contains one or more dynamic volumes

Next, I try using a VDISK. So I create one using the command prompt on the selected disk, attach it and when I refresh the installation, the disk appears in the list. I select the disk and next, it starts installing. However after extracting and installing, the following error message appears:

Windows cannot update the computer's boot configuration. Installation cannot proceed.

I have tried to run the 'Startup Repair' from the Windows 7 installation, yet the program responds by alerting "Startup Repair cannot repair this computer automatically"

I have looked all over the internet to find a solution, yet none have helped.

For any help you are able to offer, you have my sincerest gratitude.

Answer 1

See : How to Dual Boot Windows 8 with Windows 7

This article treats all of the numerous cases that you might encounter when installing Windows 7 if Windows 8 is already installed (very detailed including screenshots), as well as any problems that you might encounter during the installation process.

There is too much material in the above article to summarize it here.

But a word of CAUTION :

1. Installing Windows 7 may void your warranty.
2. Installing Windows 7 may render your Windows 8 “Recovery Partition” useless.

Answer 2

I have seen several threads regarding issues with dual-boot which supports my call for people to stop dual-booting Windows systems and start leveraging Boot to VHD.

Boot to VHD allows you to boot to a Windows 7 or later OS that installed to a VHD file and have full native access to all hardware resources. It also has the benefit of providing some portability to the operating system in the VHD (ie; move it from one machine to another if needed without bonking boot loaders or installing anything at all).

NOTE - this does not resolve issues with dual booting to NON-Windows OSes or to Windows Vista and earlier. All of these would still require you to fudge around with boot loaders and such.

You can resolve your issue by doing the following -

Add the Hyper-V role to your existing Windows 8 install. Install Windows 7 to a Hyper-V virtual machine Shut down the Windows 7 Virtual machine Copy or Move the .VHD file containing the Windows 7 OS to a folder C:\VHD.

NOTE - I recommend COPYing the VHD file and to do so BEFORE you activate. This leaves you with a Windows 7 VHD file that can be re-used with a different CD Key at a later date if needed.

Boot into Windows 8 Open Disk Manager Right Click DISK MANAGEMENT --> Attach VHD Browse to the C:\VHD folder and select the VHD file where you installed Windows 7 Finish the dialogs and verify the VHD file mounted and that drive letters were assigned to the partitions. Make note of the drive letter assigned to the partition where the /WINDOWS directory was placed for the Windows 7 install.

Keep Disk Manager open Open an Administrative level CMD prompt Execute the following command

c:>BCDBOOT ?:\windows

Where ?: is the drive letter you noted for the /WINDOWS directory above.

Reboot your system.

After the post you will see the Windows 8 boot loader ask you which OS you want of which one of those should be Windows 7. Select that and then proceed as normal.

Once you get to the Windows 7 desktop you will notice you have full native access to ALL hardware resources and you can load the latest drivers for all hardware.

There is a very, very small performance hit on disk I/O with Boot to VHD but most people will never feel it. It is in the realm of 1-2% for consumer level hardware and less for server hardware or SSD or striped disk systems.

ANOTHER NOTE - You can't do this if the C:\drive is encrypted using ANY encryption shceme. Be that BitLocker or 3rd party. The location of the .VHD file you are booting to must reside on an unencrypted volume. The volume should also be a fixed disk, not an external USB.

Answer 3

I spent 3 days on the same problem (windows 8 already installed in partition 1 and I wanted to install another windows 8 in partition 2). I just tested with windows 7 in partition 2 and it worked when I installed windows 7 through windows 8.

Instead of restarting the machine and stating windows 7 setup by USB/DVD I booted windows 8, went to My Computer, opened my usb and double clicked setup. This way I was requested to select the partition to install Win 7 (in the past I'd have get an error message saying the partition already had a windows installation. Somehow this way it worked).

After win 7 installation finished I got the dual boot from win 7 - black screen before booting to choose which windows to boot :)

Now I'm trying to run win 8 installation through win 8 installation, so I have 2 windows 8 in each partition. I'll post the results in a couple of hours

Answer 4

"Instead of restarting the machine and stating windows 7 setup by USB/DVD I booted windows 8, went to My Computer, opened my usb and double clicked setup. This way I was requested to select the partition to install Win 7 (in the past I'd have get an error message saying the partition already had a windows installation. Somehow this way it worked)."

I read this and with 'secure boot' disabled and boot mode 'legacy' I booted from a windows 7 dvd. It was prepared to permit me to install, allowed me to select a partition etc but I stopped there because I was concerned that installing win7 after Win8 might cause problems - mucking up the protective MBR.

Also, in order to boot Win 7 I presume you have to disable 'secure boot' and set boot mode 'legacy' and to boot Win 8 you had to set boot mode to UEFI.

Is that how it worked?

Answer 5

Windows doesn't like to be installed on extended or non-primary partitions, as well as on devices that aren't directly attached to the motherboard (e.g. SATA or IDE drives). The fact that you want to install it on the 4th partition tells us something. Though I haven't had to install windows on any partition further than the 2nd one, so I don't have an empirical experience on this.

You can refer to this question for more info about the maximum amount of partitions a GPT or a MS-DOS partition table can have. Quoting:

You can have 4 primary partitions, or 3 primary partitions and one extended partition containing any number of logical partitions.

Answer 6

I used a tool to accompish it. im not 100% sure this will work with windwos 8 but it worked very well with windows 7 and windows xp dual boot. The tool is called EasyBCD.