Windows 10: dual boot issue Solved

  1.    19 Jun 2018 #1

    dual boot issue


    I have a dual boot with two SSD. On both are W10 systems, let's say W10 and W10 test.
    Till yesterday it worked as follows: booting up bios; Bios (or DOS?) screen in which to select which OS. After selection immediately the selected OS system started.
    Today I updated W10 test to version 1803 and I run into boot troubles. After some repairs and new setting with easyBCD I have again the dual boot working, but not the way I prefer.
    Now after booting up the bios, a blue Windows screen appears which offers me to select one of the OS. When I select W10 an immediate start takes place. In contrast, when I select W10 test, a new bios startup takes place, which finally results in starting up W10 test. Everything takes more time.
    Any ideas what happened and how to retain the old behaviour?
      My ComputerSystem Spec

  2.    19 Jun 2018 #2

    My guess: When you setup your dual boot, (which is actually a multiboot 2 or more HDD's) (dual boot is; 2 OS's on 1 HDD), did you have both HDDs installed in the system? For a multi-boot, this is a no no as the C drive has the active MBR for both drives HDD's on it. Then go and update 1 OS and not the other, with said active MBR for both OS's on C drive, now confuses both OS's as to which is the primary for start instructions....which shows up as, in your case slow boot ups.
      My ComputerSystem Spec

  3.    19 Jun 2018 #3

    Start one instance of windows, open an admin command prompt and type

    bcdboot Y:\windows where Y is drive letter of other Windows partition.

    This will restore the menu.

    You can do same in reverse as well.
      My ComputerSystem Spec

  4. sn00ker's Avatar
    Posts : 497
    10 pro 64 clean install
       19 Jun 2018 #4

    Its probably because you have one windows license and you're using 2 hard drives . Windows is meant to be used on one license per one hard drive
      My ComputerSystem Spec

  5.    19 Jun 2018 #5

    Is one SSD MBR partitioned and the other GPT partitioned? Open a command prompt (admin) or powershell (admin) and run:

    diskpart
    list disk

    Do you have * under GPT for both SSD's?
      My ComputerSystem Spec

  6. Infrasonic's Avatar
    Posts : 49
    W10 Home 1803 / Virtual Box / Linux Mint VM
       20 Jun 2018 #6

    Plankton said: View Post
    My guess: When you setup your dual boot, (which is actually a multiboot 2 or more HDD's) (dual boot is; 2 OS's on 1 HDD), did you have both HDDs installed in the system? For a multi-boot, this is a no no as the C drive has the active MBR for both drives HDD's on it. Then go and update 1 OS and not the other, with said active MBR for both OS's on C drive, now confuses both OS's as to which is the primary for start instructions....which shows up as, in your case slow boot ups.
    This.

    I keep my 'D' HDD original copy of W10 one major iteration behind the 'C' SSD (clean install) just as a backup boot option in case C becomes fatal after a rogue update.
    Updating D will cause issues as described as both discs will start being accessed slowing everything down.
    The boot speed comes back as the iterative updates to C differentiate the two and the boot order settles down.
    A clean install on C helps, rather than a clone of D (if that was the original OS drive.)
    I've done both clean and clone, clone has a lot more D drive activity going on (task manager) even when successfully auto booting from C.

    If you put the D drive onto metered connection then you can prevent it auto updating, giving a bit more control, although you'll still probably have the MBR slowdown issue when booting from D and then going back to C.

    Edit; Also the drive letters will switch round when you boot from D, so naming drives can help avoid confusion later on...
    Last edited by Infrasonic; 20 Jun 2018 at 02:03.
      My ComputersSystem Spec

  7.    02 Jul 2018 #7

    I found out that what I observed was the effect of the Metro Bootloader, see for instance: https://www.askvg.com/how-to-disable...-in-windows-8/
    Solution was simple: uncheck in easyBCD "use Metro bootloader". Immediately the classic way of startup was restored. Problem solved.
      My ComputerSystem Spec


 

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