BSOD, error 0xc000021a

Also, I found out that the error will only pop up when I restart my laptop. When I shut down, however, it will not show an error.

No info which programm is openening this folder?

U also could boot an live linux, from there u can access the file system and delete those folders.

Another way would be the Windows 10 Recovery Tools - Bootable PE Rescue Disk
Windows 10 Recovery Tools - Bootable Rescue Disk - Windows 10 Forums

From there u can also delete those folders

Yea, it didn't say what program was using the file, but I read online to just rename it which allowed me to update and updating solved the error. Thanks for your help!

Please post the links that you used and the steps that you made to fix the problems.

I did what BSOD Hunter told me to do but I believe the main thing that helped solve the issue was updating windows to the latest version (the Creators Update).

1. I downloaded the Update Assistant here:
Download Windows 10
(click update now)

2. In my case, the Update Assistant would not work, it would say something like "Setup couldn’t start properly, Please reboot your PC and run set up again". So I did some research on this error and found this site:
http://www.thewindowsclub.com/setup-...rly-windows-10
which told me to delete the $Windows.~WS and $Windows.~BT folders

a) The ~WS folder was easily deleted, but I was not able to delete the ~BT folder. So I looked it up online and found this
site: How to remove the Windows.old and $Windows.~BT folders after you upgrade Windows
Even after using the methods from the site, however, I still could not delete the entire folder itself. Again, I looked up more stuff up online and read somewhere to just rename the ~BT folder to anything. (Can't find the site)

3. After you do this try the Update Assistant again and it should work. It will update Windows 10 and error 0xc000021a will no longer pop up.

Glad to hear that your problem is now fixed. Let us know if there are any other problems.