Fix: KB936181 Keeps Reinstalling in Windows Update: HELP! Windows Update keeps prompting to install Security Update for Microsoft XML Core Services 4.0 Service Pack 2 (KB936181). Even after installing the update multiple times, Windows Update continues to list it as a high-priority update that needs to be installed.
This issue was common on older Windows systems where MSXML 4.0 became corrupted or partially registered, causing Windows Update to believe the security patch was never successfully applied.
Important Note About MSXML 4.0
Microsoft XML Core Services (MSXML) 4.0 has been officially deprecated. It is no longer included or supported on modern versions of Windows.
- This issue primarily affects Windows XP, Windows Vista, and early Windows 7 systems
- Windows 10 and Windows 11 do not use MSXML 4.0
- If you are seeing this update on a newer system, it is likely due to legacy software
Why KB936181 Keeps Reinstalling
According to Microsoft, if Windows repeatedly asks to install KB936181 after it has already been installed, one or more MSXML system files may be corrupted or improperly registered. When this happens, Windows Update cannot correctly verify the patch state and continuously re-offers the update.
How to Fix the KB936181 Windows Update Problem
Warning: These steps apply only to older Windows systems that still rely on MSXML 4.0.
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- Click Start -> Run, type cmd, and click OK
- At the command prompt, type the following and press Enter:
ren %windir%\System32\msxml4.dll msxml4.old
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- Ignore any errors stating that the file could not be found
- Type exit and press Enter
- Manually download and install the update from Microsoft:
- Restart your computer
If all goes well, Windows Update should no longer repeatedly prompt you to install KB936181.
If You Are Using Windows 10 or Windows 11
If you are running a modern version of Windows and still see references to MSXML 4.0:
- Check for legacy applications that bundle MSXML 4.0
- Uninstall unused or outdated software
- Do not manually install MSXML 4.0 unless explicitly required
Microsoft recommends using newer XML services included directly with the operating system.
Final Thoughts
The KB936181 update loop is a classic Windows Update issue caused by corrupted MSXML 4.0 files. While the fix is straightforward on legacy systems, modern versions of Windows no longer rely on this component. If you encounter this problem today, it is almost always tied to outdated software.
Enjoy!