STOP: c000021a {Fatal System Error} 0xc0000139

An existing Critical communications error file




 is no longer valid Microsoft activesync cannot establish a connection with


the mobile device until this file has been replaced
To correct this problem, reinstall windows, or replace the file with a newer version



Note:  I am running windows XP Home edition, I copied a file from vista and tried to replace and wouldn't let me, I then renamed the existing ws2_32.dll then copied the new file in but the file reverted back to the original version. I then installed DLL REPLACER and used the drag function to move new file from desktop to new location then restarted the computer and comes up with this message


STOP: c000021a {Fatal System Error}

The windows Logon Process System process terminated unexpectedly with a status of

0xc0000139 (0x00000000 0x00000000).


and now using all options it comes up with this error.....


Can anyone please Help with this?   Thanks


Question Info

Last updated April 21, 2019 Views 4,004 Applies to:



Thank you for posting your query in Microsoft Community!


As per the description, you are receiving STOP: c000021a {Fatal System Error}.


To help you suggest steps to resolve the issue, I would appreciate if you could answer the following questions:

1.       What is the make and model of the computer?

2.       Have you made any changes on the computer prior to the issue?


You may try the troubleshooting steps provided in the link below to resolve the issue.




How to troubleshoot a "STOP 0xC000021A " error



Registry disclaimer:


To do so: Important this section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:


How to back up and restore the registry in Windows




Hope this information helps. For any further Windows related assistance, feel free to contact us and we will be happy to help.


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