Unable to boot windows 10 (0xc000021a error)

[stapleshotz]

So I made the mistake of following the steps in this video without looking into it more before hand, and after I restarted my machine it was unable to boot, giving me a frowny face and the 0xc000021a error. (I've done some searching and didn't find anybody else with a similar problem related to this error)

I tried booting into safe mode, but it resulted in the exact same error. After trying a few more times, I decided to attempt a reset. On the first try I selected "keep my files" and it started the reset but then stopped, saying it encountered a problem and that nothing was changed. I tried again, this time selecting "reset everything". It started but was stuck perpetually at 1% (the "Resetting: 1%" thing was also only visible for about half a second every 20 seconds or so. No idea why.) I left and came back about 2 hours later to find it still stuck at 1% so I turned it off.

It booted back up with the same error as before. My computer was a prebuilt machine but I've since replaced the MOBO and graphics card, so that may have something to do with the reset not working (I have almost no idea what I'm talking about though so maybe not)

I was able to access a command prompt in the startup settings menu thing, but I don't know what to do with it.

I haven't tried booting from a usb yet, though maybe that will bear fruit. I don't actually have a copy of windows I can put on one though. (Windows 7 pro 64bit came pre-installed and I upgraded to 10.)

I'm kind of out of ideas here so any suggestions would be greatly appreciated.

 

[thejackal85]

If you're getting those errors it looks like we're running into some incompatibility here. I just answered a post similar to this a few hours ago.

If the processes of Windows 10 are failing out like resetting or rolling back, then there is definitely something hardware wise interrupting what is going on. Because at that point, since the OS is fresh (sort of), it's looking at what it's physically working with and not so much software.

My best piece of advice would be to revert back to Windows 7. I know you said you followed a video that I didn't watch and you don't have an actual copy of the CD, but during the Windows 10 upgrade, did you format the drive or just do a straight upgrade? Because if that's the case, your computer may have a restore partition on the HDD with Windows 7 you can use. Doing a google.com search on your make/model will tell you.

 

[stapleshotz]

If you're getting those errors it looks like we're running into some incompatibility here. I just answered a post similar to this a few hours ago.

If the processes of Windows 10 are failing out like resetting or rolling back, then there is definitely something hardware wise interrupting what is going on. Because at that point, since the OS is fresh (sort of), it's looking at what it's physically working with and not so much software.

My best piece of advice would be to revert back to Windows 7. I know you said you followed a video that I didn't watch and you don't have an actual copy of the CD, but during the Windows 10 upgrade, did you format the drive or just do a straight upgrade? Because if that's the case, your computer may have a restore partition on the HDD with Windows 7 you can use. Doing a google.com search on your make/model will tell you.

Thanks for the quick response!
When I upgraded to 10, I just did a straight upgrade. Shortly after, I replaced the MOBO which gave me a whole new set of issues since my windows license was OEM. I had Microsoft tech support set up a new license for me.

Perhaps because of all that, there doesn't appear to be a system restore point saved anywhere. (I will certainly be setting one up after I get this issue resolved)

I'd rather not buy a whole new license of windows to fix the one I already own, so maybe I can try downloading one? Probably not the safest bet, but if it's already broken...

 

[thejackal85]

If you revert back to Windows 7, you should be able to use the same license your computer came with.

Okay, when you boot your computer up, there should be a button designated for "restore" or something of the like. Go into that and it should open up a menu, does one of those have the factory reset option in it? If so, you won't have to worry about a key, it will use the pre-installed one on the image.

 

[stapleshotz]

If you revert back to Windows 7, you should be able to use the same license your computer came with.

Okay, when you boot your computer up, there should be a button designated for "restore" or something of the like. Go into that and it should open up a menu, does one of those have the factory reset option in it? If so, you won't have to worry about a key, it will use the pre-installed one on the image.

Ah that's what you meant. Well that's what I tried doing when it got stuck at 1%. I actually left it on for several hours last night and it still hadn't moved. I don't know if it's because my original license for windows 7 was OEM and I have a different mobo now or what, but I don't think reverting to factory state is an option for me.

My friend has a bootable windows usb stick so I'm gonna try that today and see how it goes. Fingers crossed.

 

[thejackal85]

Yeah, the bootable stick should work for reinstalling Windows and that should resolve your issue. I would hold off on upgrading to Win10 for a while, lol.

 

[stapleshotz]

Yeah, the bootable stick should work for reinstalling Windows and that should resolve your issue. I would hold off on upgrading to Win10 for a while, lol.

It worked! I had a bit of trouble reformatting the drive so that it could install, but I'm all set up now. Thanks for your help!