Windows 10 quality updates explained and the end of delta updates
Published Jul 11 2018 11:06 AM 241K Views
Microsoft

Update 2/5/2019: Based on customer feedback, we are extending Delta update publication for Windows 10 versions 1607, 1703, 1709, and 1803. We will continue to provide Delta updates via the Microsoft Update Catalog through April 9th, 2019, which will be the last delta update available.


With Windows 10, quality updates are cumulative. Installing the most recent update ensures that you receive any previous updates you may have missed. We used a cumulative update model to reduce ecosystem fragmentation, and to make it easier for IT admins and end users to stay up to date and secure. However, cumulative updates can prove challenging when it comes to the size of the update and the impact that size can have on your organization’s valuable network bandwidth.

When a new Windows 10 feature update is released, the first cumulative update is generally between 100-200 MB in size. Across all versions of Windows 10, cumulative updates grow as additional components and features get serviced, pushing the size to somewhere between 1-1.2 GB. Generally, this happens within the first 6-8 months after the release of a feature update.

To help you reduce the burden on your network bandwidth, yet still receive the same equivalent update, Microsoft designed three different update types:

  • Full updates have all the necessary components and files that have changed since the last feature update. We refer to this as the latest cumulative update, or LCU. It can quickly grow to a little over 1 GB in size, but typically stays that size for the lifetime of that supported version of Windows 10.
  • Express updates generate differential downloads for every component in the full update based on several historical bases. For example, the latest May LCU contains tcpip.sys. We will generate a differential for all tcpip.sys file changes from April to May, March to May, and from the original feature release to May. A device leveraging express updates will use network protocol to determine optimal differentials, then download only what is needed, which is typically around 150-200 MB in size each month. Ultimately, the more up to date a device is, the smaller the size of the differential download. Devices connected directly to Windows Server Update Services (WSUS), System Center Configuration Manager, or a third-party update manager that supports express updates will receive these smaller payloads.
  • Delta updates include only the components that changed in the most recent quality update. Delta updates will only install if a device already has the previous month’s update installed. For example, assume in May that we changed tcpip.sys and ntfs.sys, but did not change notepad.exe. A device that downloads the delta update will get the latest version of tcpip.sys and ntfs.sys, but not notepad.exe. Delta updates include the full component (not just the individual files) that changed. As a result, they are larger than express updates, often around 300-500 MB in size.

Regardless of which type of update is installed on a device, that update is fully cumulative and installing the latest update will ensure that the device has all the necessary quality and security improvements.

update-size.png

This raises an important question: why make delta updates available if express updates are more optimized and don’t require the previous month’s update already be installed? Delta updates were originally created because the express update protocol was only available to devices connecting directly to Windows Update or Windows Server Update Services. In January 2017, the express protocol was extended to all 3rd party update management systems; however, we continued to ship delta updates to give companies and third-party update management tools time to implement support for express updates.

Currently delta updates are available for the following versions of Windows 10:

  • Windows 10, version 1607
  • Windows 10, version 1703
  • Windows 10, version 1709
  • Windows 10, version 1803

Now that express update support for third-party update managers has been available for over a year, we plan to stop shipping delta updates. Beginning February 12, 2019 Microsoft will end its practice of creating delta updates for all versions of Windows 10. Express updates are much smaller in size, and simplifying the cumulative options available will reduce complexity for IT administrators.

For more information on optimizing update bandwidth and more details about express updates, see Optimize Windows 10 update delivery. To learn more about Windows as a service, check out the new Windows as a service page on the Windows IT Pro Center.

60 Comments

We may not like the feature release process them but that's why they are increasing the window of support to 30 months for enterprise folks.  If you are on Pro you can skip a feature release but for sure you can't be on a two year old platform.  It is what it is.  It won't change for 1709.   There's other patches you are missing out on and not just the RDP ones.   I'm on 1903.  1803 was very stable for me.  Pick one feature release a year.  I don't install feature releases right away, I wait a month or two to let issues shake out.  Like I said, there's a patch management community at www.patchmanagement.org that lots of admins can help you out.

 

Even with "regular updates" there's still going to be a feature release support window.   That won't change.  Bottom line, establish a testing process, reach out to fellow patchers.

Copper Contributor

I understand your point, but it is not that simple in a corporate environment. We are at the mercy of our third party vendors to ensure they are testing and releasing updates supporting the latest version(s) of Windows. We have already run into a load of issues with different software vendors, where we have upgraded, and then are waiting of them to update their software and products which directly affects the productivity of our users. It is what it is, but I still don't think the window is long enough for vendors to support the releases.

 

Just my opinion.

Which is why the fall releases of windows 10 on the enterprise sku have a 30 month support window.  Microsoft agrees with you.  But not on the pro sku.

Copper Contributor

This blog post is rather old, but it seems to be using terms incorrectly and that is confusing. The Author keeps using 'quality' to describe the update that is the subject of this post "Windows 10 quality updates explained and the end of delta updates" and "With Windows 10, quality updates are cumulative.") when it appears that he is actually referring to Feature updates. 

The issue is that Microsoft has labeled the current updates in the Mainstream Build channel as 'Feature' or 'Quality' updates. The Feature updates have a cadence of twice a year because they are in the Long Term Servicing Channel (LTSC), and the Quality updates are monthly (see this site ) because they are in the Semi-Annual Channel (SAC). Additionally, as further confirmation of the terminology, at this site the acronyms LCU and SUU are defined as Feature and Quality respectively.  

However, in this post, the term 'quality' is used repeatedly at the beginning, but then phrases like "When a new Windows 10 feature update is released...", or "...first 6-8 months after the release of a feature update.". The times referenced also point to a Feature update instead of a Quality update. This is confusing for those trying to learn the Microsoft update process as it exists today. Replacing the word 'quality' with "Feature" would go a long way toward clarifying this post. 
Thanks. 

Copper Contributor

Please help me my (cumulative update 2019-4 ) is not istall in my laptop.

Spoiler
 
Microsoft

DTP6144: 
Quality updates refer to the monthly updates that contain quality fixes (security and other bug fixes).  In the site you linked to that explains LCU and SSU terminology you'll see that the person who answered the question was actually incorrect the first time and referred to LCU's as feature updates.  In a later response they clarified and stated that LCU's are quality updates.

The correct answer is more complicated though: LCUs can actually be used for both quality updates and feature updates.  LCU is a way to compress and package component changes together so they can be installed successfully.  The component changes themselves could include bug fixes (quality update) or features (feature update).  The decision to label something a quality update or feature update is a policy decision and isn't limited by the technology that supports the update.

I hope that helps instead of making it even more confusing :)

Microsoft

ritiksagar1441: Do you have an error code you've received when you try to install the update?  One thing that may help is to uninstall your latest update, then click to search for updates again and download and install the latest.  2019-4 is an update from April so there should be a newer one available.

Copper Contributor

Well it's safe to say Windows10 version 1511 will not be receiving updates. 

If I could where would I start.

Copper Contributor

If fixing the NTFS.sys failed Error is an issue. Do check out the steps to fix it here: NTFS.sys failed

Copper Contributor

this all sounds very good

 

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