WIndows dual-boot issue....

[#1]

hi all,

I had a Windows 7/Windows XP dual-boot system.

I upgraded the Windows 7 partition to Window 10 under the "free upgrade" program (months ago).

Post upgrade testing showed everything looking good - could still alternatively boot into Windows XP.

Didn't notice any issue until a few weeks ago, when I needed to boot to XP to access an old app that only runs under XP - and then got one of the dreaded boot error messages, something like "NTOSKRNL.EXE is missing or corrupt".

There are many tutorials out there on fixing this issue, usually about booting from original install disk into Repair Mode, etc. - but none seem to cover the situation where XP is the 2nd OS on a dual boot.

I have tried to simply replace the ntoskrnl.exe file for the 2nd partition/OS whilst booted into the 1st (Win10) - but that didn't work.

Obviously I don't want to put my Win10 primary OS at risk - but does anyone have any suggestions as to a relatively safe approach to fixing boot issues with my (obsolete and unsupported - but stupidly useful) Win XP partition...?

Thanks,

[#2]

You could see if the problem is a corrupt boot configuration data store which is pointing to the wrong place.

I am not an expert at doing this, but a quick Google suggested that if you open an administrative command prompt window and type BCDEdit, you will get command line access to the configuration data store. (It works here on Win 10 - I get information about the boot, but I don't have dual boot system).

Instructions on what BCDEdit can do are at https://technet.microsoft.com/en-GB/library/cc709667(v=ws.10).aspx

Be careful!!

[#3]

If the message you are getting if true then you need to replace ntsokrnl.exe with a good copy.  It lives in %SystemRoot%%\System32 on the XP partition.  You can do that from Windows 10 using your XP disc as the source (or you can probably find an online copy).

If Wisty is correct then if you use the Windows 10 boot loader you could restart holding down the Shift key then navigate to the option that lets you run a CMD prompt.  Then use the bootrec tool i.e. bootrec /scanos then bootrec /RebuildBCD if necessary.  That saves you messing around with BCDEdit.  There are more details here: https://neosmart.net/wiki/bootrec/ - its the same as in Windows 8/8.1

[#4]

when you say partition I take it you mean both os on a single hard drive ?

if yes then you need to copy your xp partition to a separate hard drive for dual boot to work, otherwise you will have the exact same problem every time you try and use xp after using 10.

once you have the two os's on separate hard discs you can enable boot choice in the bios and select which drive to boot from, if your using a laptop or don't have the space to fit a secondary hard drive, enable boot from usb and either copy the xp partition to a thumbdrive or external hard disk and boot from that (hard drive would be better given the re-write cycle limitations on thumb drives)

its down to the secure boot feature of windows 10 that re-writes the mbr to prevent non w10 booting when not using a VLK (enterprise) product based on the average pc users inability to understand security.... stupid for the minority that have half a clue (or more) but brilliant for the majority who don't

[#5]

there is a way round it - apparently

http://www.tenforums.com/installation-setup/20482-windows-10-xp-dual-boot-best-way.html

http://www.tenforums.com/general-support/20424-unable-start-windows-xp-after-windows-10-upgrade.html

[#6]

I have a system the dual boots between Windows 7 and Windows 10 (the latter upgraded from Windows 8.1).  Both versions of Windows are on the same hard drive on different partitions.  If I tell the machine that Windows 10 is the default choice it uses the Windows 10 boot loader.  If I tell it that Windows 7 is the default choice it uses the Windows 7 boot loader.  There are no problems.  Now admittedly Windows XP is further removed from Windows 10 than is Windows 7 but I don't think that should make dual-booting impossible or even as difficult as some here suggest.  Oldjim's solutions seem to be simply about editing the Boot Configuration Data file.  You can do that manually, which isn't pleasant.  You can use EasyBCD, which is easy apart from the fact that you have to register to download it now.  Or you can try to get Windows to do it for you in the manner I suggested earlier.      

[#7]

Yesterday I took a computer that had previously been temporarily upgraded to Windows 10 then reverted to Windows 7 after problems arose with some installed software.

1. I shrank the System partition ( C: ) to create extra space towards the end of the hard drive
2. I made an image of the hard drive (using Acronis True image).
3. I deleted the System partition then wrote it back so the free space was before that partition rather than after it.
4. I deleted the small (100MB) System Reserved partition at the start of the drive.
5. I installed Windows 10 into the free space at the start of the drive.  It activated automatically because of the previous brief upgrade.
6. I used Shift+Restart to get to the Advanced Options and selected Command Prompt.
7. I ran bootrec /RebuildBCD.  It found the Windows 7 partition and I instructed it to add that partition.
8. Hey presto, I have a computer that dual boots between Windows 10 and Windows 7.

This is only a temporary measure but it allows some programs to be run in Windows 7 until I can find Windows 10 versions or alternatives.  I did not need to delete the System Reserved Partition but did so because Windows 10 prefers it to be larger (250MB) and I knew how easy it was to make the computer dual-boot thereafter.

[#8]

Reed,

An alternative is to install a copy of VirtualBox (its free) from Oracle and set up your windows 7 system as a Virtual machine. If you use Win 7 in what is called seamless mode under Virtualbox  then you get an additional taskbar for the WIn7 system just above the standard Windows 10 one, and any application you run on Win7 appear as just another window on your desktop.

Map your data files between the two systems and the two sets of applications coexist on the desktop (almost) seamlessly.

I use this setup to run an old program that will only run in a 32bit environment on a Windows 10 64 bit box.

[#9]

Yes, I've never got around to trying a virtual machine.  In this instance there is no point unless you can virtualise an existing Windows installation.

[#10]

There is a help section on the VB site - Migrate_Windows - which details transferring XP. I've not tried it, though.

Edit: A method I have used (10+ years ago) is explained in this blog , but you need SP2 tools (from SP2 file support\tools\deploy.cab) to use it (MS no longer have sysprep at the link in the blog). You may, if I recall correctly, need to use device manager to delete all the hardware specific devices in the list so that the first boot of the image searches for devices and installs drivers (as OEM installations do).

Phil

[#11]

There is a Microsoft tool at https://technet.microsoft.com/en-us/sysinternals/ee656415

which will convert a live system to a VHD virtual disk. I believe Virtualbox will run a VHD format system disk - I haven't tried it but the instructions for doing so are around. You could also try enabling Microsofts Hyper-V on the Win 10 box and use that, but I prefer Virtualbox.

I think the best way is to convert the VHD you created  to  a native Virtualbox VDI format using the tool at https://forums.virtualbox.org/viewtopic.php?f=6&t=22422   and use that as the basis for the virtual machine.

There may then be a bit of faffing around with hardware - its a while since I virtualised my XP system - and some hassle with licence activation - but it certainly works.

[#12]

Hi all,

Thanks for all the replies. The reference to bcdedit (thanks @wisty) reminded me that some time ago I had downloaded/successfully used EssyBCD - so downloaded the latest and created a new entry in the Windows Multi-Boot menu for the existing WinXP instance (which, for reference, is on the same HD) - and it worked. Successfully booted into WinXP.

Having got in, applied a load of updates that were outstanding due to not having booted into it for some time - 3 x MS Updates, Comodo AV updates and an odd Skype update. Rebooted - selected WinXP from the Boot menu - and the PC rebooted. Can't get into XP now - no error messages, just reboots almost as soon as I select WinXP from the boot menu (even trying safe mode crashes/restarts).

So, one problems solved, another created. Usual PC troubleshooting..!!!

Thanks again for the pointers - will need to wait until next weekend to carry on....