Windows 10: BSOD 0xc000021a - Cannot boot Win 10 at all

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  1. Posts : 11,489
    Windows 10 Pro
       16 Jul 2016 #31

    Or, if there was a way to turn off Windows Resource Protection temporarily whilst sfc could do its stuff, that might fix it.
    Not possible, Windows Resource Protection is SFC.

    Is there a way to boot from the drive in a caddy so that I can eliminate the mobo disk controller?
    I do not know, doesn't often happen that someone wants to do that.
      My ComputersSystem Spec

  2.    19 Jul 2016 #32

    Update:


    Hi guys,

    Still waiting for my new HDD. Supplier sent me a faulty one (wouldn't format) so I had to return it and get a replacement (just bad luck I guess).

    While waiting, I decided to get hold of a copy of Rufus and make a Windows to Go USB drive to see if I could get the errant machine to boot with that. If it booted, my rationale was that this would prove that all the hardware was fine.

    I only had a 64GB standard USB 2.0 drive to hand so I decided to use that. Drive imaged out ok (took hours!) and eventually I had a bootable Windows 10 USB stick. I used Rufus 2.0 and a Win10 iso downloaded from MS Techbench.

    Moment of truth... I put the SUB stick in, configured my BIOS to boot it and... It booted up just fine! Ok, the system was VERY SLOW, snail pace even but I know that this is due to the crappy drive read/write performance. However, it does at least prove that my hardware is working ok (that is, of course, it eliminates everything but the HDD controller itself).

    So, it looks like we're coming back to the HDD or the Windows image on it. This does eliminate a pile of things though. It took about a day to get the stick imaged and loads of time to set it up but now I know how to do this, I think I will buy a high-speed stick so that I can always have a portable Win 10 system on hand.

    When my new drive arrives I will try a clone of my existing drive first, and if that doesn't yield any results, I'll put a new Win 10 install on it and we'll see what happens then. See you on the other side!
      My ComputerSystem Spec


  3. Posts : 11,489
    Windows 10 Pro
       19 Jul 2016 #33

    I have a retail key for Windows 7 Pro, which is what I upgraded this system from. I guess I could in that case get the key deactivated/reactivated again. I suspect I'll have to do that again anyway if I try to reinstall onto a new disk. We'll have to wait and see.
    I mentioned that the replacement of a motherboard means a new system, a new system requires new activation.
    If you replace anything else, you won't have to activate it again
    With the upgrade your hardware has been registered on the servers of Microsoft, this activation is called a digital entitlement. Basically means it that you could reinstall Windows as often as you like, whenever you like, without activating

    Let me say it again ONLY if you replace the motherboard the system requires a new activation, with any other hardware replacement no activation is required.
      My ComputersSystem Spec

  4.    19 Jul 2016 #34

    axe0 said: View Post
    I mentioned that the replacement of a motherboard means a new system, a new system requires new activation.
    If you replace anything else, you won't have to activate it again
    With the upgrade your hardware has been registered on the servers of Microsoft, this activation is called a digital entitlement. Basically means it that you could reinstall Windows as often as you like, whenever you like, without activating

    Let me say it again ONLY if you replace the motherboard the system requires a new activation, with any other hardware replacement no activation is required.
    Should be simple then. Hopefully all will go without a hitch. I'll report back when it's done. Maybe it will throw up something else!
      My ComputerSystem Spec

  5.    21 Jul 2016 #35

    gaztech said: View Post
    Should be simple then. Hopefully all will go without a hitch. I'll report back when it's done. Maybe it will throw up something else!
    Still waiting for my HDD !!

    I've been experimenting with WMIC again. I need to ask a question:

    Using WMIC in my recovery environment it seems to work well to list things like running processes and hardware. However, when I try to run it to interrogate something where it would need to get the data from, say, the registry, it fails.

    I'm trying to run a very simple command to get the list of installed programs.

    wmic product get Caption, InstallDate, Vendor

    What this "should" do it list installed program names, date of install and the manufacturer. I can run this on my Win10 laptop from a command line and it works. (Of course though this one is actually "running" Windows at the time).

    However, every time I run it in my recovery environment on my borked machine, it fails with an error - Invalid Class. It's easy to get a list of the classes that are used and supported, just type WMIC /?. All the info comes up. Therefore my installed program class "Product" should be supported. (Actually it's win32_Product).

    Other queries that require access to the operating system also fail. It's as though the WMIC command has access to memory and all hardware but it doesn't have access to the Windows 10 operating system on the disk so it can't query it. The PATH statement just points to the RAM drive X: when in recovery mode. I also added the C: drive to the PATH as well, thinking that this would enable access but it still won't work and tell me what is installed on the drive!

    I wanted to do this because I've read that Windows 10 sometimes has an issue with Kaspersky Anti Virus. I thought that if I could get the installed name from the system I could use WMIC to do a proper command-line uninstall of it. Issue is that if I can't get access to the "Product" alias, it won't work.

    Looks like another MS recovery tool that won't work unless Windows is actually RUNNING. What's the point?

    Maybe I'm doing something very stupid here (very likely - and I'll freely admit it if I am) but can anyone point me in the right direction so that I can make this work?

    Oh, and I've also tried using the alias for the "uninstall" registry key too - but that doesn't work either, presumably for the same reason as the "Product" alias.

    To recap, all WMIC commands that rely on interrogating hardware work fine. Also interrogating services, (presumably because they are in memory) works. Trying to access anything else won't work (could it be Windows Security getting in the way?). Of course, I'm running from an elevated "Administrator" prompt in the recovery console.

    We'll get there... Just seems like a hard slog no matter what I do...

    Anyone have any input to this? Am I being very stupid?
      My ComputerSystem Spec

  6.    23 Jul 2016 #36

    UPDATE:

    An interesting thing has popped up... I got my new HDD and decided not to clone the other drive immediately but I thought since WIn10 free upgrades end this month it would make more sense to install a fresh copy of Win 7 Pro using my retail key and upgrading that.

    I had a hell of a job when I upgraded this initially in December and found I had to use an iso burned onto a flash drive to get the OS installed an upgraded. Any other method simply wasn't having it. It did work from the flash drive though so I assumed I'd have to do the same thing with this new install.

    Installed Win7 thenI decided to check everything before I did all the updates required to convert to Win 10. I found that instead of the Marvell 91xx HDD controller showing in Device Manager, it had the Microsoft "generic" IDE ATA/ATAPI controller sitting there.

    I've had issues with this on workstations before (don't know why I didn't think of it). If the BIOS is set to IDE - not AHCI then WIndows will fail to load the correct driver. Before I installed Win7 I tried to install Win10 directly but it flatly refused to do this. I thought it was probably due to the HDD controller driver so I obtained the correct one and tried to load it. Windows refused. Of course it would if AHCI was not enabled in BIOS.

    I'm now going to research this. What if a Windows update had loaded on my borked system that specifically requires AHCI??? If that happened then it's always going to fail. More research required. Will do that and report back...

    Watch this space...
      My ComputerSystem Spec

  7.    25 Jul 2016 #37

    Final Update:

    Ok, so forget everything that's gone before. I now know what the issue is - trouble is I can't solve it.

    I did all the stuff to get my (new) HDD to AHCI and found a driver. All worked ok for the Win 7 install (I was going to upgrade that immediately) but... I found that Windows 7 kept crashing. This was a vanilla installation with ONLY SP1 installed. Huh?

    Most things worked but if I used anything like IE which required the machine to actually do something at least 8/10 it would crash.

    This was now pointing to hardware!

    I decided to do a fresh install of Win 10 on my new HDD to see what happened there...

    Install would NOT complete, kept giving me odd errors until the final one that pointed to the real issue:

    Error told me that memory address xxxxxx (not sure what it was) could not be accessed. I made a note of the address and calculated it. This address was well within the amount of RAM installed so I went hunting... I'd messed around with ram, moving sticks and I'd even replaced it with some different RAM from a friend that had some spare. Same result for everything so I discounted the RAM and moved on to other things. It couldn't be that ALL the sticks I had (I had 7) would be faulty could it? Nah...

    I'd messed around with overclocking the RAM, using XMP options and DOCP but none of these worked. I still had issues.

    Whilst messing around with the BIOS I found a screen, buried deep in the BIOS that showed the amount of RAM installed. It was reporting exactly HALF of what was there. Further investigations resulted in finding out that no matter what was physically installed, it ALWAYS reported half the ram - even if there was only one stick in there. Why this information is not reported on the first BIOS screen is a complete mystery!!! I'd always had "quick boot" turned on so I never got to see what the motherboard was reporting. I'd checked it in Windows before and it always showed the correct amount so it didn't occur to me to check further.

    I'm 100% convinced now that this is my problem. Windows is trying to either test on bootup for this missing RAM or simply has issue with the BIOS and its own reporting - thus the C000021a error.

    I've tried all the usual... re-seating ram, checking slots, blowing it out, checking the processor seating and cleaning it. Tried nulling the CMOS, leaving the battery out and re-finding RAM. My motherboard even has a MEM-OK function which is supposed to find odd combinations and put whatever right, but that fails to actually report correctly too.

    I'd been having a few crashes before I got the terminal C000021a error and a reboot usually solved the issue. Then it crashed the last time and I was unable to resolve the problem. I'm sure this is it. It all makes sense.

    Time to replace the motherboard. Nothing else I can do. Just for once, I'm pretty sure the issue isn't with Windows at all.

    So, there you go. It has taken me days of grief but at least I can rest easy knowing that I've actually found something concrete to base the problem on. I'm hacked off of course - but pleased to know that after all the testing something has finally come out of it.

    Many thanks for all who contributed here. I wouldn't have gotten to this point without you.

    Thanks guys!
      My ComputerSystem Spec


  8. Posts : 11,489
    Windows 10 Pro
       25 Jul 2016 #38

    That is a very well done troubleshooting process you've done
    Glad to hear you've found the problem
      My ComputersSystem Spec

  9.    25 Nov 2016 #39

    Same problem after win update


    axe0 said: View Post
    That is a very well done troubleshooting process you've done
    Glad to hear you've found the problem
    Exact problem. checked memory and it is half after update. how is that possible. mother board had 16 before and running boot programs since that is all I can do they read two four sticks in there now??? 11/25/2016
      My ComputerSystem Spec


  10. Posts : 11,489
    Windows 10 Pro
       25 Nov 2016 #40

    Smittyken said: View Post
    Exact problem. checked memory and it is half after update. how is that possible. mother board had 16 before and running boot programs since that is all I can do they read two four sticks in there now??? 11/25/2016
    Create a new thread for your problem, then we can provide better support.
      My ComputersSystem Spec


 
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