Windows Stop code 0xc000021a


Posts: 941   +225
TechSpot Elite
Hey Guys;

I am getting a lot of calls for PCs crashing on startup with Windows Stop code 0xc000021a

On the first one System Restore was turned off (weird) so I couldn't use that. I used the Windows 10 version of MSconfig to try a modified boot. I tried turning off 'Startup items' and then I added 'services' but it still failed to boot in both cases. Safe mode works.

On the 2nd machine, I just tested if it would go into Safe mode and it did that with no problem.

In both cases, I am electing to rebuild the machines since that is usually a known path to success. What brought this on is a mystery. The machines are approx 5 years old and both run SSD drives, from different owners. Was there some kind of recent Microsoft patch that is borking machines?

I just got the 3rd one in the shop today. A Lenovo Thinkpad laptop today.


Posts: 2,564   +3,139
Staff member
Every time I've come across this BSOD error, when fixing PCs, it's nearly always been down to a corrupted registry. Isolating the causes of that problem is nigh on impossible, simply because of how many things can cause it -- iffy hardware, people installing junk apps, people uninstalling stuff they think isn't important but is, kids messing about with the family PC trying to 'improve' it, power surges, family cat giving the computer the evil eye, and so on.

It could easily be a Windows 10 or 11 update, but with so many rolled out for the different versions, analyzing them all to find which one might be the root cause probably just isn't worth the time and effort. Your preferred choice of solution (full rebuild) is certainly the most sensible one to do.


Posts: 89   +2
The 0xC000021A error can occur if there were corrupt system files in the computer, a failed upgrade, or an incomplete installation of a software program.

I copied & pasted from a google search shown above.

I have that one when a hard drive is going bad.
Hard disk sentinel can be downloaded and used for
free. The standard version. It shows when a hard drive
has little life left and some bad sectors.

[HEADING=2]Hard Disk Sentinel - HDD health and temperature monitoring[/HEADING]


Posts: 941   +225
TechSpot Elite
Oh yes, I 'Googed it up' to wondering why there was a sudden rash of failures. I pretty much found what you guys are talking about. A generic error with many possible sources. Thanks for your input guys. =)