Error 0xc0000021a - want to reset but Product Key doesn't work

[Serpico89]

Hello, I' am currently using a custom made laptop which I had to repair due to an hardware failure. After I got the PC back I reinstalled Windows but the product key I had wasn't working properly any more. Knowing that after an hardware change this is not an uncommon problem, I just used the option "Activate by phone" and everything went fine.

Unfortunately the last day I got the blue screen with the error 0xc0000021a, which I know is caused by misconfigured system files in the computer. Moreover this error is really similar to the error I got prior the hardware failure (0xc00000e). So I figured that maybe the Windows 8 installation I have (I purchased before Windows 8.1) has some problems, and maybe I can solve them by reinstalling directly Windows 8.1, instead of reinstalling Windows 8 and then upgrading it from the store.

The problem is that when I launch the Windows 8.1 set-up program to create a media for recovery, when asked for the product key mine doesn't work. I think this has something to do with the hardware change and with the fact that I used the "activate by phone" option, but my Windows version is legit and I paid for it, and therefore I want to be able to reset my computer if I need to (like now).

Anyone has any suggestion on how to solve this? Thank you

 

[johnbl]

the product key used for the download is not tested for activation. It is tested for a valid key. Most often people just mistake some of the characters
and enter the wrong sequence. for example:
i,1
0,o
G,6
b,8
m,rm

I think 0xc0000021a is a failure cause by corruption of the windows logon service
windows detectes its process memory image had been modified and it shuts down windows.
I would run a malwarebytes scan to check for a virus attempting to hack windows.

also, start cmd.ex as a admin (windows key+x then type A)
dism.exe /online /cleanup-image /restorehealth

this will go to a trusted online source and repair corrupted key windows files.