Downgrading from windows 7 gone wrong (bootmgr is missing)

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  1. Posts : 20
    Windows 7 Professional x64
       #1

    Downgrading from windows 10 gone wrong (bootmgr is missing)


    Hi all. So I was trying to deinstall windows 10 and install windows 7 of my Asus Vivobook S300C using this guide.

    Everything worked fine until the "IMMEDIATELY Click Out On Top X, TERMINATE Installation Process and REBOOT." step. At this point I restarted the computer and continued through the installation process to the point where I was supposed be able to click "INSTALL NOW". Here I got the message

    "A required CD/DVD drive device driver is missing. If you have a driver floppy disk, CD, DVD, or USB flash drive, please insert it now. Note: If the Windows installation media is in the CD/DVD drive, you can safely remove it for this step." <Browse> <OK> <Cancel>.

    After a bit of googling I found this site which suggested the problem might be caused by the fact I was using a USB 3.0 port. I indeed was using a USB3.0 port so I turned off the computer and put the USB drive in a 2.0 port instead. However, now when I turn on the computer I get the message "BOOTMGR is missing. Press Ctrl+Alt+Delete to restart". When I go into Bios the USB stick isn't even there in the boot options anymore (just the hard drive of the laptop).

    I tried making a new bootable USB stick but still get the same problem. Any ideas as to why this could be?

    Thanks in advance!
    Last edited by IFTN; 22 Oct 2016 at 06:00.
      My Computer


  2. Posts : 13
    Windows 7 Ultimate x86
       #2

    go to the bios then set your boot order..
    IF DETECTED THEN DO THIS

    1.Load Windows through any drive USB or DISC
    2.Click Repair your Computer
    3.Find the O.S. you want to repair
    4. Go to System Recovery Options then click COMMAND PROMPT
    5.Type in Command Prompt this Bootrec /RebuildBcd

    IF STILL SAYING
    "A required CD/DVD drive device driver is missing. If you have a driver floppy disk, CD, DVD, or USB flash drive, please insert it now. Note: If the Windows installation media is in the CD/DVD drive, you can safely remove it for this step." <Browse> <OK> <Cancel>.

    TRY RE-DOWNLOADING YOUR ISO THEN USE RUFUS OR WINDOWS USB/DVD Download Tool
      My Computer


  3. Posts : 20
    Windows 7 Professional x64
    Thread Starter
       #3

    Hi, thanks for the response but the USB doesn't even show up in the boot order anymore. I tried making a new bootable USB (with rufus) but still doesn't show up (which is weird because it did at the first try). And the laptop has no CD drive.
      My Computer


  4. Posts : 7,351
    Windows 7 HP 64
       #4

    Witch OS came with the laptop, Win 7, 8 or 10?
    Witch OS was on the laptop before win 10, Win 7 or 8?
    You where trying to roll back from Win 10 to Win 7 or you are trying to do a clean install?
    Where did you get the Win 7 Pro disk?
    Did you change any BIOS settings?

    - First of all, the link you have followed is 4 years old and is for a Legacy MBR.
    - Your Laptop is 2 years old, and has a UEFI BIOS, not a Legacy MBR.
    - Win 7 installation disk doesn't have USB 3 drivers, so it ask for CD/DVD drive device driver. You must use USB 2 or provide the USB 3 drivers.
    - Secure boot isn't compatible with Win 7. You must disable it on BIOS (Boot menu).
    - What configuration is on CSM on BIOS (Boot menu)?

    Give me the information I asked and I'll try to guide you.
    Last edited by Megahertz07; 22 Oct 2016 at 08:47.
      My Computers


  5. Posts : 20
    Windows 7 Professional x64
    Thread Starter
       #5

    Witch OS came with the laptop, Win 7, 8 or 10? 8
    Witch OS was on the laptop before win 10, Win 7 or 8? 10
    You where trying to roll back from Win 10 to Win 7 or you are trying to do a clean install? Clean install
    Where did you get the Win 7 Pro disk? Got the iso from the windows site
    Did you change any BIOS settings? No (other than boot order)

    Thanks for your help!
      My Computer


  6. Posts : 7,351
    Windows 7 HP 64
       #6

    First of all, you have to change some BIOS settings so it will be compatible with Win 7.
    - Download the User guide https://download.lenovo.com/ibmdl/pu...e540_ug_en.pdf
    - On page 135 (119) USB - Set USB 3.0 Mode = Disabled (enable AFTER win 7 installation)
    - On page 138 (122) SATA Controller Mode = AHCI
    - On page 140 (124) Security Chip = Inactive
    - On page 142 (126) Secure boot - Set Secure boot = Disabled
    - On page 142 (126) Secure boot - Set Platform Mode = User Mode
    - On page 143 (127) Secure boot - Set Secure Boot Mode = Standard Mode
    - On page 144 (128) UEFI/Legacy Boot - set UEFI Only + UEFI First + CSM Support = yes
    - On page 144 (128) Boot Device List F12 Option = Enabled
    - On page 144 (128) Boot Order Lock = Disabled

    - Disconnect all other drives - Very important
    - Boot with your Win 7 64 bits installation disk on UEFI mode
    - Select custom (advanced) - drive options - delete all partitions - create new. Windows will create the necessary partitions and install.
    Clean Install Windows 7

    To save time on the updates:
    MS releases SP2 for Windows 7

    For drivers an documentation Laptops-and-netbooks :: ThinkPad-Edge-laptops :: ThinkPad-Edge-E540 - Lenovo Support
      My Computers


  7. Posts : 20
    Windows 7 Professional x64
    Thread Starter
       #7

    Hi! Thanks very much for your answer, but that's for the wrong laptop! I'm working with an Asus Vivobook S300C - I can't even find half the options you're talking about
      My Computer


  8. Posts : 7,351
    Windows 7 HP 64
       #8

    Sorry, my mistake.
    Start over.
    - You must place the USB Flash disk on a USB 2.0. Win 7 Installation disk doesn't have USB 3 drivers.
    - How did you installed the Win 7 Installation into the USB Flash disk? (witch tool you used?)
    - With version you are trying to install, 32 or 64 bits?
    - Win 7 isn't compatible with Secure Boot. It must be disabled. And CSM must be enabled.
    - Disable Fast Boot
    Attached Thumbnails Attached Thumbnails Downgrading from windows 7 gone wrong (bootmgr is missing)-a_boot.jpg  
      My Computers


  9. Posts : 13
    Windows 7 Ultimate x86
       #9

    From what I know every OEM laptop come with a Recovery Partition I think you can use that to reinstalll Windows...
      My Computer


  10. Posts : 20
    Windows 7 Professional x64
    Thread Starter
       #10

    Megahertz07 said:
    Sorry, my mistake.
    Start over.
    - You must place the USB Flash disk on a USB 2.0. Win 7 Installation disk doesn't have USB 3 drivers.
    - How did you installed the Win 7 Installation into the USB Flash disk? (witch tool you used?)
    - With version you are trying to install, 32 or 64 bits?
    - Win 7 isn't compatible with Secure Boot. It must be disabled. And CSM must be enabled.
    - Disable Fast Boot
    I'm using Rufus to make the USB stick. 64 Bits. Already had Secure Boot disabled and CSM enabled. I can't find the option for fast boot though?

    EDIT: My screen looks almost the same as yours, the only difference being that I have version 2.15.1226 and apparently fastboot doesn't show up
      My Computer


 
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