Update on 17th Nov 2021 – Microsoft announced that Microsoft removed the semi-annual channel update for Windows 10 on Nov 16, 2021. There will only be one feature update per year for Windows 10.
I wondered whether there is any difference in the content of Windows 10 ISO files released in two phases. There are two different ISO files released as part of Windows 10 SAC-T and SAC channels.
More details about the Semi-Annual Channel are here. In this post, we will see the differences between Windows 10 SAC-T and SAC ISO Media.
Two Related posts on Windows 10 Servicing Topic
Windows 10 1709 Semi-Annual CBB Ready for Broad Deployment and details about the release date of Windows 10 1709 CBB version media
Release management strategy of Windows 10 Servicing – Real-World Experience.
Content of this post
Windows 10 Patching – Avoid Fragmentation
ISOs Released part of SAC-T and SAC have the Same Content?
What is the Difference Between Windows 10 SAC-T and SAC ISO Media content?
Conclusion
Windows 10 Patching – Avoid Fragmentation
With Windows 10, patching is simpler with one cumulative monthly update that supersedes the previous month’s update, containing security and non-security fixes.
Another fact pointed out by Microsoft was most of the production Windows 7 and eight machines don’t have the same patch level. The cause of the fragmentation of patches is a mix of individual updates, as explained in the following diagram.
What is the big deal with the fragmentation of patches in systems? As per Microsoft, “Fragmentation where different PCs could have a different set of updates installed leading to multiple potential problems”.
I recommend avoiding FRAGMENTATION of patches on Windows 10 machines from starting itself. So, I wanted all the Windows 10 computers in my network to have the same patch level.
Hence I had a valid question about different Windows 10 ISOs released in SAC-T and SAC channels. More details about Windows patch fragmentation.
ISOs Released part of SAC-T and SAC have the Same Content?
No, the content of both ISOs is different. Windows 10 Semi-Annual Channel (Targeted) (e.g., released on 17th OCT 2017) ISO and Windows 10 Semi-Annual Channel ISO (e.g., will be published on 22nd Jan 2018) have different content. Windows 10 SAC-T and SAC ISO media are different.
In a scenario:- If I deploy 30% Windows 10 devices with SAC-T channel ISO and 70% Windows 10 devices with SAC channel ISO. Does this have a chance of fragmentation of patches on Win 10 systems? I hope it won’t create fragmented systems because of the cumulative nature of Windows 10 patches.
Update (18th Jan 2018) – I discussed a Twitter with Cristopher Alaya on patch fragmentation. And as per him, the fragmentation would still be there. “There are updates deployed by Microsoft Update which are not included in the Cumulative Update, like the Servicing Stack update here:
https://support.microsoft.com/en-us/help/4058702/servicing-stack-update-for-windows-10-version-1709 … It’s not in the CU.”
So, ideally, you are safe to start the development of the Windows 10 core image for SCCM immediately after SAC-T ISO availability. My previous post, “Release MGMT strategy for Windows 10 Semi-Annual Channel and SAC-T releases,” has more details.
But to avoid fragmentation of patches in systems, you need to inject patches released between SAC-T and SAC releases into your latest Windows 10 image. Another way to prevent fragmentation of patches is to keep all your Windows 10 systems up to date with the latest patch(s).
What is difference Between Windows 10 SAC-T and SAC ISO Media content?
We found that Windows 10 SAC-T and SAC ISO Media are different in the above section. In this article, we will get more details about the details of this difference. I was trying to find out an answer to the above question. I didn’t find a clear-cut answer on TechNet documentation.
Microsoft deliberately uses the word “Refreshed media” to refer to the Windows 10 SAC ISO. As an SCCM admin, I don’t believe both REFRESH and UPDATE are the same in this scenario as well.
I assumed, and Michael confirmed through Twitter that “We do refresh the media for convenience, adding in a later cumulative update“. He gives a perfect example to make me understand the difference between the Windows 10 SAC-T and SAC ISO Media content.
“So it’s the same BASE BUILD (e.g., 16299) but a later PATCH LEVEL (e.g., 16299.15 vs. 16299.125)”.
Conclusion
Windows 10 BASE Version is the same for both Semi-Annual Channel (Targeted) and Semi-Annual Channel.
For example
Windows 10 1709 SAC-T Base version is 10.0.16299
Windows 10 1709 SAC Base version is 10.0.16299
Windows 10 1703 SAC-T Base version is 10.0.15063
Windows 10 1703 SAC Base version is 10.0.15063
The difference between Windows 10 SAC-T and SAC ISO Media is PATCH LEVEL. Windows 10 cumulative Patches are the only difference between the Windows 10 ISOs released as part of the CB and CBB cycle.
You can check this out in the following examples.
Windows 10 1709 SAC-T PATCH LEVEL is 16299.15
Windows 10 1709 SAC PATCH LEVEL is 16299.192 (I’m not sure Windows 10 1709 SAC ISO patch level until 22nd Jan 2018)
So, you can start building or creating Windows 10 images within SCCM once the CB or SAC-T version of Windows 10 is released. No need to wait for the CBB version of Windows to get published.
Update on 17th Nov 2021 – Microsoft announced that Microsoft removed the semi-annual channel update for Windows 10 on Nov 16, 2021. There will only be one feature update per year for Windows 10.
Author
Anoop is Microsoft MVP! He is a Solution Architect in enterprise client management with more than 20 years of experience (calculation done in 2021) in IT. He is Blogger, Speaker, and Local User Group HTMD Community leader. His main focus is on Device Management technologies like SCCM 2012, Current Branch, and Intune. He writes about ConfigMgr, Windows 11, Windows 10, Azure AD, Microsoft Intune, Windows 365, AVD, etc……………