Dual boot Windows 7 and Windows 8 then remove Windows 7 RRS feed

  • Question

  • Hi,

    my plan is to install Windows 8 on a Windows 7 computer on a new hard drive creating a dual-boot system. Once I have Windows 8 setup properly with apps etc. I want to remove the Windows 7 install and use the old drive for data. what are the steps for this?


    Thursday, August 30, 2012 6:42 PM

All replies

  • In the process:

        • Install a second hard drive
        • Install Windows onto it
        • Make that Windows installation your default
        • Delete the old Windows installation on the first drive

    What parts of which steps do you need help with?

    • Edited by JustinCoon Thursday, August 30, 2012 8:50 PM
    Thursday, August 30, 2012 8:50 PM
  • I installed Windows 8 on a separate HD.

    Now I want to remove Windows 7. Windows 8 is active and default but I can't delete Windows 7. If I unplug the Windows 7 HD, Windows 8 is not starting up. I also removed the Windows 7 startup entry in msconfig but Windows 8 is still looking for Windows 7.

    How can I fix this?

    Friday, August 31, 2012 1:07 AM
  • @mz7thc

    You should be able to do this

      • Boot into Windows 8
      • Open Disk Management (From your desktop hit the Win + X keys and choose Disk Management)
      • Right-click on your (C:) drive in either section of the list and select Mark Partition as Active
      • Open a Command Prompt as Administrator (Win + X keys and choose Command Prompt (Admin))
      • Run this command: bcdboot c:\windows /s c:
      • Try booting to Windows 8 without your first disk now.
      • If that doesn't work, try booting off your Windows 8 installation DVD, go to the command prompt there, and run: bootsect.exe /nt60 all /force
      • If you don't have the installation DVD you can download bootsect.exe (google search),  boot to Windows 7, copy it to the C:\Windows folder, and run it from an administrative command prompt there.
      • Don't forget to configure your BIOS to boot to your Windows 8 disk when you put the old disk back in.

    • Edited by JustinCoon Friday, August 31, 2012 1:48 AM
    Friday, August 31, 2012 1:47 AM
  • Thanks JustinCoon,

    I opened a Command Prompt as Admin and run "bcdboot c:\windows /s c:"

    Got the reply: Boot files successfully created.

    Tried booting Windows - got a disk read error

    Started Windows 8 installation DVD, run "bootsect.exe /nt60 all /force" - was successful except for one instance

    Restarted - got a disk read error again

    Not sure what else to try, I don't want to reinstall everything again.

    Friday, August 31, 2012 4:44 AM
  •   I am not sure how you got yourself into trouble. As JustinCoon said in his original post, it is pretty straight forward.

       Here is how I did it.

       Installed Windows 8 to run from second disk multiboot. Had no problems booting into either.

       When I didn't need Win 7 anymore, went into bcdedit and deleted the config for Win 7. Machine now booted directly into Win 8 (no other boot option).

      Reformatted original HDD.



    Friday, August 31, 2012 5:37 AM
  • I'll list out the requirements for getting Windows to boot. You might find that it will take you less time to unplug your Windows 7 disk and reinstall Windows 8 than try to troubleshoot. You might also try the Repair option that should be on the Windows 8 DVD. You'll have to use Google to figure out exactly what your configuration is and possibly how to do some of these things. 

    First, if you have a GPT partitioned disk you have to have a EFI BIOS to be able to boot off it with normal Windows tools. You can switch a disk from GPT to MBR but you'll probably lose everything on it with normal Windows tools. Maybe something like gparted can change the partition scheme without destroying the data. Disks greater than 2 TB have to be GPT. On the other hand if the disk is MBR partitioned (as is common) then it "should" be straightforward. 

    You need to have:

    • A partition on your disk Active (what you did in Disk Management) (It possibly has to be the first; see my comment later)
    • The bootloader installed on that partition (what bootsect does)
    • The BCD store for that bootloader to boot Windows (what bcdboot does)
    • Your BIOS has to be booting to this disk as well

    If you look in the lower section of Disk Management you might see that there's another (probably unnamed) partition before your C drive. Try this:

    • Make that first partition the Active partition.
    • Unplug the Windows 7 disk
    • Boot to the Windows 8 DVD
    • Run bcdboot c:\windows (note: without the /s c:)
    • If bcdboot complains, try: "bcdboot d:\windows" or "bcdboot e:\windows" in case the drive letter of your Windows installation shifted.

    • Edited by JustinCoon Friday, August 31, 2012 6:28 AM
    Friday, August 31, 2012 6:27 AM
  • @Dave59boulder

    Seeing the trouble that some people have with multiple disks, you might want to unplug your Windows 7 disk while you're installing Windows 8 and then add it back later. That will ensure your Windows 8 disk can boot on its own. 

    Once you're in Windows 8 you can type "bcdboot z:" where z: is the drive letter of your Windows 7 disk; that will add a Windows 7 option to your Windows 8 bootloader. 

    Friday, August 31, 2012 6:34 AM
  • Just noticed when I unplug a disk which is not related to Windows (e.g. MyDocuments), Bios is still pointing to the right boot disk, I get also an read error and Windows does not start. That means if I have to change my disks at some stage, Windows won't boot anymore...

    There should really be an option during installation of Windows 8 to configure it as stand alone or dual boot. I never expected to run into trouble.

    Friday, August 31, 2012 7:03 AM
  • that seems like a cool idea. never heard this before. anyone else try this?
    Friday, August 31, 2012 11:44 AM
  • Very nice! I'm going to use procedure. Have two questions though:

    In my case I partitioned/shrunk WIN 7 drive and installed WIN 8 on new partition. Will procedure still work?

    Second question is that my WIN 8 is the downloaded upgrade version that needs to see previos os. If I remove the previous WIN 7 could that cause problems down the road? Such as if I wanted to from scratch reload WIN 8 would I have to put WIN 7 on first again then install WIN 8?


    • Proposed as answer by Ed Grey Thursday, December 6, 2012 7:06 PM
    • Unproposed as answer by Ed Grey Thursday, December 6, 2012 7:06 PM
    Thursday, December 6, 2012 2:37 PM
  • 1. Remove your old HDD with windows 7.

    2. Plug in your new HDD.

    3. Insert your installation DVD and install windows 8.

    4. Boot into windows 8, download and install EasyBCD .

    5. Shutdown. Plug in the old HDD. Boot into bios and make sure your boot order is NewHDD / OldHDD. Otherwise will boot directly windows 7.

    6. Enter windows 8 and using EasyBCD edit your boot loader to add Windows 7 as a dual boot if you like. If not.. just hit "run" then type diskmgmt.msc

    7. Format OldHdd.

    Is simple as that. Now, if you install windows 8 on a second partition is even more simple.

    1. Create a new partition as "primary" type.

    2. Reboot and install Windows 8.

    3. At first boot into windows 7, google EasyBCD . Download and install. It's free.

    4. Edit your boot loader adding windows 8 as Dual Boot.

    5. Reboot, now you should have the option to choose. Enter windows 8.

    6. Important ! Install  EasyBCD here. Use it to remove windows 7 from boot, leaving only windows 8 . Hit run, type: diskmgmt.msc . Set windows 8 partition to "Active". Reboot.

    7. If everything is ok, now you should be able to format your C:\ partition hosting windows 7. You will notice that at first reboot your drive letters will change. The active partition hosting the OS will be renamed to C:\ :)

    Succes !

    Thursday, December 6, 2012 7:54 PM
  • I believe it depends on your Windows 7 installation and what order the partitions are in. If Windows 7 created its recovery partition first and that's the active partition you should be fine. Check for a relatively small, active unnamed partition before your first Windows partition. 

    Regarding the upgrade, Windows 8 shouldn't care if you delete the Windows 7 partition. I don't know if you'll have issues reinstalling later but you might be able to make a system recovery image of your Windows 8 installation and restore from that if you need to reinstall. I'm really only familiar with the enterprise environment. 

    Thursday, December 6, 2012 9:16 PM
  • 1. Remove your old HDD with windows 7.

    2. Plug in your new HDD.

    3. Insert your installation DVD and install windows 8.

    4. Boot into windows 8, download and install EasyBCD .

    5. Shutdown. Plug in the old HDD. Boot into bios and make sure your boot order is NewHDD / OldHDD. Otherwise will boot directly windows 7.

    6. Enter windows 8 and using EasyBCD edit your boot loader to add Windows 7 as a dual boot if you like.


    Ed, I tried this method to dual boot and failed. I have a ssd disk as my C drive with windows 7 64. I also have a 2 tb D drive for scratch and pictures, Video etc.  I then installed W8 on a new Hd. easy bcd displays W7 and W8. When i reboot i have the choice of Os but only W8 boots no matter what I choose? Please advise!
    Saturday, March 2, 2013 5:15 AM
  • Same here, it didn't work for me either.

    I had a Windows 7 harddrive, shrunk the partition, created a new NTFS simple partition in the free space on the end of the drive, and installed Win8 in that new partition.

    Now I want to stick with Win8 and delete the Win7 partition.  I'd also like to move the Win8 partition to the beginning of the drive (cause it's faster there).  Here's what I did, I rebooted after every step:

    1. Set the Win8 partition to "active", reboot.

    2. go into msconfig, delete the entry in 'boot' tab for Windows 7, check 'make settings permanent', reboot

    3. go into bcdedit, delete windows 7 bootloader, reboot.

    4. Delete Win7 partition.

    5. Bootup fails (obviously, because bootmgr was on Win7 partition), use Windows Recovery Disc to recreate new bootmgr and boot loader on Win8 partition.

    6. Boot success!  So far so good, I now have a working Win 8 partition on the end half of the drive, and free space on the beginning half of the drive.

    7. Use Easeus Partition Manager to move the Win 8 partition to the beginning of the drive, reboot, get BCD NOT FOUND error (or something along those lines)

    8. Try Windows 8 repair disc, auto repair, windows 8 tries to boot, gets stuck at Welcome... screen with spinning dots, then crashes and screen turns yellow/red stripey.  Rebooting then shows the BCD NOT FOUND error again.

    Is it even possible to move a bootable Win 8 partition without breaking it?  Or should I just give up and reinstall everything?

    Sunday, July 7, 2013 8:14 PM
  • This worked perfectly for me :D
    Saturday, January 25, 2014 7:27 PM
  • hi, dave 

    my name is anmol 

    you should first format the windows 7 install and  then go to open charms bar by pressing windows key+c and then search and type computer management and in computer management go to disk management and at the bottom you will se many partitions.then you should deleate the windows 7 install partition by clicking right mouse button and then choosing delete partition.

    i hope this will help you.

    Friday, January 31, 2014 4:56 PM