Windows 10 update screwed dual boot system - STUMPED!!

[Carol Haynes]

I 'had' a dual boot system of Windows 7 Ultimate on hard disk and Windows 7 Pro on an SSD!

Windows 7 Ult is my main OS on a large hard disk and I used the free period to install upgrade to Windows 10 on an SSD in dual boot mode to get the free license for future upgrade.

I use Windows 10 on my laptop all the time so rarely on my desktop PC which usually boots into Windows 7.

Dual booting has worked fine and I could use the system properties to set the default operating system (worked fine).

Stupidly yesterday I booted Windows 10 and decided to run Windows update and leave it over night. Because it had a Windows version update to do I switched to automatically boot into Window 10 so it could get on with it while I was asleep.

Got up this morning to a blue screen"DPC_WATCHDOG_VIOLATION"

I rebooted and on restart got missing/damage \Boot\BCD error with error code 0xc000014c

I thought - no big problem and bunged in Windows 10 Recovery CD and booted from that - it failed to find Windows 10 - instead it found Windows 7 Ult (phew) and the legacy Windows 7 Pro folder (Windows.old which is still there from the Windows 10 upgrade).

After a lot of faffing, swearing and stomping around, and in the end using a windows 7 recovery disk, I finally managed to get Windows 7 Ult running again.

Anyone any idea how to fix the Windows 10 installation to dual boot again so that I can try to get it running and updated properly?

I am stumped - almost all the info I can find on dual booting is a mix of Windows and Linux.

To give a bit more description:

When Windows 7 was set as default the 'Select operating system' screen during boot up was the Windows 7 version, but when I switched to Windows 10 default it swapped to the Windows 10 version.

Also no I can find a Boot folder on either drive (hidden or not)

[Shades]

You could try and take a look with 'EasyBCD'to see how your current BCD looks like and this software gives you a good idea how to add your Windows 10 back into the BCD.

If you take a look at your hard disk with Eindows own partition manager ('Disk Management' section of the 'Computer Management' administrative tool), you will see a small partition (100 to 300 MByte) that is usually in front of the main partition(s) on the first hard disk (Disk 0) in your computer. That little partition is where the boot information from both your Windows versions reside. When Windows has started, this little partition is not accessible...as in not showing up in any file manager you care to install in either Windows 7 or 10.

But with 'EasyBCD' you won't have such a hard time fixing things inside this little partition. This change in the Windows boot procedure was introduced in Windows Vista and is activated when you do a clean install  on a new hard disk...or when you do a clean install overwriting content of the boot partition of a used hard disk. The creation of this little partition doesn't happen when you, for example, upgraded from XP to Windows 7 and chose to not alter anything in the partition structure on that disk during this upgrade.

The default option, when you do a clean install of Windows 7, it ask you permission to create that little partition. And then you are stuck with it, for as long as you don't re-install.

By adding the SSD the Windows 7 Pro installation detected that the first disk already had that little partition and instead of creating that little partition on the 2nd disk, it uses the one of the 1st disk.The upgrade to Windows 10 detected the BCD settings from Windows 7 Pro and adjusted these.

This implicates that if your Windows 7 Ultimate disk develops any kind of hardware problem, you won't be able to continue working with Windows 10, because that little partition is missing from the Windows 10 boot procedure too. It is likely (but not a given!) that the Windows 10 repair disk will be able to make your Windows 10 disk boot-able. But without such a disk? You will be cursing at everyone and everything during the complete re-installation.

Oh, you think you covered this by creating an image to spool back in case of an emergency? Most image software doesn't get the boot-procedure from a dual-boot system right, especially when that little boot partition does not reside on the disk you are creating the image from, so you will be in the same mess, except with old(er) versions of your files.

Generally speaking, never ever have 2 empty hard disks connected for the creation of a dual boot system. Because then Windows will "decide" which disk gets that little partition where both versions of Windows will boot from. You'd better know the boot order set in your UEFI/BIOS and the numbering of the SATA connectors on your motherboard by heart to have an educated guess which disk will get that little partition. Better connect one disk, successfully install the first version of Windows, then connect the second disk to complete the dual boot setup.

[Carol Haynes]

Back to square one - just a windows 10 style blue screen saying Boot\BCD is missing or corrupt error 0xc000014c

I have made a Windows 10 recovery CD on my laptop - automated repair hasn't worked so I tried firxmbr, fixboot and rebuildbcd options - it doesn't even find windows 10. No change after that lot

I did the same with a Windows 7 repair disk, automated repair said it was fixed but it wasn't. I even used Microsoft's instructions to backup/delete/rebuild the BCD info which I did only adding the original Windows 7 Ultimate as an option.

I still get the Windows 10 style error screen

What is odd is that the Boot\BCD folder isn't on either of the Windows partitions??? It is on another drive altogether

Any other ideas - I got Windows 7 up and running again once but on restart I was back to the same pale blue screen???

[Shades]

This partition is what my previous post was talking about:


Windows 7 installers create a partition of 100MByte, the Windows 2012 installer I used created a partition of 350MByte. But that might also be caused by the SSD.


No Boot\BCD folder in C:\ or anywhere else Windows allows access to for that matter. You will find all the boot info in that little partition.


With EasyBCD you can create/restore backups from the BCD information in that little partition. And you can edit it too.

The EasyBCD website I linked to in my previous post also has a boot disk on offer with repair tools for the BCD information. Which is really starting to sound like the solution to your problem.

[Carol Haynes]

Thanks - seem to have 'almost' recovered Windows 7 but the windows 10 upgrade via windows update has hosed the SSD completely - files are still readable but there isn't an OS installed on there.

I seem to have a boot folder and bootmgr in that little partition as well as on C: and another hard disk.

I think the one on C: is the one being used

Got to the point where I can't face any more! At some point I will do a clean install!

[Carol Haynes]

Should the windows partition be set to an active partition or should it be the small system partition set to active?

[ajlixx]

it is probably another problem - creators update contains small cmd based applet called mbr2gpt, which convert mbr disk to gpt disk without files loss - i have read that it should be used through cmd, but i met on other forums at least 1 case where, it seems, it got at work automatically and tried to convert disk to gpt - it is especially provided for 7 to 10 upgrade cases, because 7 doesnt serve fully uefi

if it is your case you should ascertain what is exactly partition style on yor booting disk, i mean disk set in uefi\bios as booting - you could do it for example with partition wizard bootable cd started from cd - if it is gpt style there will be small 100mb partition efi on disk formatted in fat32 - and then use system applet bcdboot to write bootloader files to this partition (or just from 7 installer cd, using diskpart commands list disk, etc)

dual boot system is in this case of no consequence - you should be always able to add other 7 to bcd in case of problems

what partition should be active - of course with folder boot and bootmgr file - in partition wizard you can check folders\files on partition - just to mark partition and choose explore partition in menu - but only on mbr disk of course; system partition 100mb on mbr will be formatted in ntfs, not fat32

in gpt style disk there is no active partition - instead is system partition efi (esp - efi system partition), with windows boot manager files

sorry for my english, but i am in great hurry!

eventuallly, if you can use bcdboot, from installer cd or from recovery partition\folder, if possible (or from system, is in system32) - command something like

bcdboot c:\windows /s x: /f uefi

/s x: means

system partition letter = x: - you should assign letter to efi for example in diskpart, or in partition wizard, because normally this partition is without letter - letter is of no consequence for functioning because partition is recognized by uefi by guid in gpt partition table, not letter, letter is only for bcdboot to identify it; x of course only example

or maybe there are other commands in bcdboot automatically recognizing system partition efi without letter - i am no expert in bcdboot

another possibility - you should make functional 7 on hdd, and repair start on ssd from this 7, for example using easy bcd - easy bcd could repair both mbr and gpt start

to make funcional 7 on hdd you should mark partiton as active in diskpart, write codes on start sector of disk and active partiton (from cd - commands bootrec /fixmbr, and /fixboot), and write bootloader to active partition, command in bcdboot in 7 (all this with detached ssd)

bcdboot c:\windows /s c: /f mbr

to write bootloader bcdboot uses boot files templates from system registry folder, so you would not have systems choice in 10 - you should add both 7 to new bootloader in easy bcd

on hdd you can have mbr style, only on booting ssd gpt\uefi - partition style on data disk is of no consequence

to use bcdboot is probably important, because there are slight differences in bcd file for mbr and gpt; but easy bcd also can write right bcd

[Carol Haynes]

Sorry I am being dense but I didn't follow most of that - both installations were on MBR format disks.

I currently have 6 hard disks in my system plus an SSD drive (Disk 0 - still labelled Win7ProSSD because I never got round to changing the label to Windows 10)



They are all MBR disks apart from Disk 5 - which is a 3Tb data GPT drive

The system currently books from disk 1 (which was the first drive to have windows installed on it when I built the original system.

The System Reserved folder on disk 1 has a BOOT folder and bootmgr system file

During all the recent messing about I set the Windows 7 (C:) partition active and that now too has a BOOT folder and bootmgr system file

Should I set the System reserved partition as the active partition and remove the extra boot info from C:

Also at some point M: (which is on the GPT drive) also acquired a BOOT/bootmgr setup - I don't know when this happened as the drive was added to the system after the SSD but before I upgraded to Windows 10 on the SSD.

I presume the boot config appeared on M: when I upgraded to Windows 10 but was unaware that had happened.

I am not really that familiar with disk formats and the boot process - how can I best recover the boot system to make Windows 7 on C: the only boot option (which it currently is) using the original boot process - and can I then delete the extra BOOT/bootmgr bits on the other drives.

If at that point I start installing a freshly downloaded Windows 10 onto the formatted/SSD what effect will that have on boot processes?