How to fix
Msxml4.dll Error with an Error Code 0xc000012f
on Windows

When I try to open AVS programs, I get an error message, which says that msxml4.dll is missing or cannot run on Windows. I tried reinstalling the software and rebooting Windows, but the same error reappeared. What would you recommend?

“C:\\Windows\\System32\\Msxml4.dll is either not designed to run on Windows or it contains an error.” That’s a notification received by many Windows users, especially those running Windows 10 Creators Update (C1703). The error is usually marked with an error code 0xc000012f, which assists people if they attempt to search the web for the bug.

“Msxml4.dll is either not designed to run on Windows or it contains an error” alert may be caused by many different reasons, for example, virus infection, fragmented system files, missing/corrupted registry entries, software conflicts, and similar. However, the 0xc000012f error shows up exclusively when trying to launch certain software installed on the system. It may affect one specific program and that may be a sign that a problem is directly related to some components of that app or the system’s components that are necessary for launching it.

If, nevertheless, Msxml4.dll error shows up when trying to run several apps, most probably there are some internal Windows bugs that are preventing the system from running the apps. Luckily, there are several methods that may help you to fix “Msxml4.dll is either not designed to run on Windows or it contains an error” error on Windows.

C:\\Windows\\System32\\msxml4.dll is either not designed to run on Windows or it contains an error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support. Error status 0xc000012f

A guide on how to fix “Msxml4.dll is either not designed to run on Windows or it contains an error”

Statistically, more than a half of errors on Windows are triggered by malware/virus. Therefore, it’s necessary to check the system for malicious apps and files despite the fact what kind of pop-up alert you receive. For this purpose, we recommend using [d1]. This utility encompasses the management of Windows OS in terms of virus/malware attack and condition of system’s components.

If the system is virus-free, we would recommend performing Clean Boot to check for software conflict. If that did not help as well, please refer to the following Msxml4.dll error fixes:

Fix 1. Register Msxml4.dll

• Right-click Windows key and select Command Prompt (Admin).
• Click Yes on the UAC.
• Copy and paste the following commands into Command Prompt and hit Enter after each:
  regsvr32 /u msxml4.dll
  regsvr32 /i msxml4.dll
• Now close Command Prompt and restart the program that triggers Msxml4.dll error.

Fix 2. Remove Junk

• Press Windows key + R, type cleanmgr and hit Enter.
• Then select OS partition that you want to clean and press OK.
• Select Clean up System Files and wait for the process to finish.
• Restart Windows after all.

If neither of the two methods helped, you may try to check for available Windows updates. In addition, open Device Manager and expand all section of the device drivers. If any of the drivers are marked with a yellow exclamation mark, click it and select Update Driver Software.

The last recommendation would be to enable the System Restore Point. If the “C:\\Windows\\System32\\msxml4.dll is either not designed to run on Windows or it contains an error” pop-up started emerging only recently and all the affected programs were perfectly running in the past, you may try to enable the Restore Point. However, there’s one important condition – you must have created such a point before the problem occurred.