A lot of classic software is reaching end-of-life (EOL) this month. Windows 10, Office 2016 and Exchange Server 2016 have survived after nearly a decade of service. Not far behind, after six years in existence, comes the end of Office 2019 and Exchange Server 2019. While this Patch Tuesday may be cause for celebration at Microsoft with the final updates for these products, I hope you’ve been following this closely and have already migrated to newer versions of these products. If not, this month, I’ll review some of the options available.
Microsoft Office 2016 and 2019 reach end of life
Let’s start the EOL discussion with Microsoft Office, where both the 2016 and 2019 versions will receive their final updates this month. Until October of 2024, Microsoft Office 2016 was THE standalone office suite of choice. With the end of Office 2016 imminent, your choices for a similar support model are Office 2024 or Office Long Term Service Channel (LTSC) 2024.
These are available without the Office 365 Apps subscription, they come with a fixed set of applications, and they will be supported through October 2029. The LTSC version is for more specialized devices in environments with limited connectivity. The migration selection for most Office users is to upgrade to Microsoft 365 Apps, which comes with all types of licensing, as well as comprehensive security and ongoing feature upgrades.
The one thing to keep in mind is that you should quickly update to new versions of applications like Project and Outlook, which have an extended calendar and daily use aspect, to minimize your security and operations risk.
Migrate to Exchange Online or subscription edition
Next up, we have the EOL of Microsoft Exchange Server 2016 and 2019. Another product providing nearly a decade of service, Exchange Server 2016 migration is closely tied to your decision on the Office upgrade. If you are moving to Office 365 Apps, you should consider migrating to Exchange Online. If you want to remain with an on-premise solution, your choice is to upgrade to Exchange Server Subscription Edition, which was introduced in July.
Microsoft provided a detailed roadmap back in 2024 on how Exchange Server 2019 would be upgraded to Exchange Server SE over time. Pay close attention this month if you are upgrading because Microsoft expects to release Exchange Server SE CU1.
Final Windows 10 update arrives before ESU begins
And finally, the biggest EOL of all, Windows 10, goes into Extended Security Updates (ESU) after this Patch Tuesday. Windows 10 was released on July 29, 2015, to a lot of fanfare, after the dismal performance of Windows 8.1. It signified a significant switch in Microsoft strategy to the SaaS model with annual version updates.
Internet Explorer was replaced with Microsoft Edge for better performance, and its more modular security nature, allowed for significant security updates each month.
Microsoft surprisingly committed to three years of ESU updates once it became apparent that worldwide updates to Windows 11 were hampered by the steep hardware requirements.
The final version of Windows 10 22H2 will be released this month and is required if you plan on using the ESU. The first ESU patches will show up in November. Regardless of your situation, the clock has started ticking and it is imperative to upgrade to a fully supported OS as soon as possible.
It’s not all nostalgia this month. Microsoft released a new major operating system version – Windows 11 25H2, in contrast to all these soon-to-be EOL products. This new release can be easily installed through a feature update enablement patch KB5054156 if you are running Windows 11 24H2. Updating from any other version requires a full OS installation. This is considered a minor update with ‘better vulnerability detection’ as the only noted security feature.
October 2025 Patch Tuesday forecast
- This is a critical month to bring your soon-to-be EOL systems and applications up-to-date with their final patches. Download and deploy the expected usual OS, Office and SharePoint patches. The .NET core versions have been getting updates, but we haven’t seen a security update for .NET framework in a while, so be on the lookout.
- Adobe Illustrator and Photoshop in the Creative Cloud suite didn’t receive updates last month, so pay attention to those apps. Adobe Acrobat and Reader received an update in September, but never counted out another one.
- On September 29th, Apple released macOS Sonoma 14.8.1, macOS Sequoia 15.7.1, macOS Tahoe 26.0.1, and iOS/iPadOS 18.7.1 and 26.0.1 to address CVE-2025-43400. It may be a while until we get another security update, but make sure you have this one covered.
- The Google Chrome release from September 17th addressed CVE-2025-10585 which is the sixth zero-day vulnerability of the year. Expect another update next Patch Tuesday but be aware they are often seen late in the day.
- If Mozilla doesn’t provide a major release in the next day or so, you can expect one next week. The last major security update across their main and ESR product set was way back on September 16th.
It’s hard to believe that Microsoft Office 2016, Exchange Server 2016 and Windows 10 have all been around in general service for over a decade. Except for the LTSC versions with their more targeted use, we will probably never see everyday applications in support for such an extended period again.
