# Microsoft Update Releases

I frequently get pinged on when a new Cumulative Update gets published on Microsoft Update Catalog, and why it is not in OSBuilder. I hope this will clear a few things up.

## LLCU

I posted previously on this last week, and maybe Microsoft reads my stuff and decided to clarify things ;)

{% embed url="<https://www.osdeploy.com/osbuilder/updates/latest-lcu>" %}

## Microsoft's Take

[Michael Fortin](https://blogs.windows.com/windowsexperience/author/michaelfortin/) (Microsoft Corporate Vice President, Windows) explains in some detail about the different updates

{% embed url="<https://blogs.windows.com/windowsexperience/2018/12/10/windows-monthly-security-and-quality-updates-overview/>" %}

And here is the important stuff ...

![](/files/-LTd6x950h1W8vJbwb_D)

## WSUS Updates

These updates will consist of the "Patch Tuesday" (B Release) and the on-demand updates. C and D releases are considered "Preview Releases". This explains why you don't see them in WSUS

## Microsoft Update Catalog

The [Microsoft Update Catalog](https://www.catalog.update.microsoft.com/Search.aspx?q=Cumulative+Update+Windows+10+1607+x64) will contain ALL releases. Patch Tuesday Releases will be classified as Security Updates

![](/files/-LTd9_jJwYWZfUute4gN)

## Windows Update History

Another method to determine the Latest Cumulative Updates is to view the Windows 10 Update History page.

{% embed url="<https://support.microsoft.com/en-us/help/4000825>" %}

This will detail the updates that appear in the Microsoft Update Catalog (ALL Releases)

![](/files/-LTdAOCnrvVIchcjmWQV)

## OSBuilder

OSBuilder Update Catalogs are generated from WSUS, so these will include the "Patch Tuesday" (B Release) and any On Demand Releases (Critical). C and D Releases can be added to OSBuilder using [**`New-OSBUpdate`**](broken://pages/-LSwcBpuvhvL9-xsX6xN), but at least consider that these are Preview Releases and probably should only be used for Testing, and NOT for an Enterprise Deployment, but that's your call.

## Further Reading

{% embed url="<https://www.forbes.com/sites/jasonevangelho/2018/12/12/microsoft-admits-normal-windows-10-users-are-testing-unstable-updates/#53d0f7814f6f>" %}


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