Outdated Software You Should Stop Using in 2026

Old software has a nasty habit of looking perfectly healthy. It opens, it prints, it saves. Nothing on screen tells you that the vendor stopped fixing it two years ago, and that's exactly what makes it dangerous.

This list is the 2026 version: the discontinued tools we still find on business networks, the dates they stopped getting security fixes, and what to replace them with. Some are ancient. A couple went off support in the last few weeks.

Why "it still works" isn't the same as "it's safe"

Here's the mechanism most people never hear about. Every month Microsoft releases security patches for the products it still supports. The moment a patch is published, attackers can compare the patched file with the old one and see exactly which piece of code was fixed. That tells them where the hole is.

Now think about an unsupported product built on much the same code. It has the same hole, but it will never get the patch. Each month's fixes for supported versions effectively hand attackers a fresh map of weaknesses in the unsupported ones. The longer you run old software, the longer that list of known, permanently open holes gets. It only ever grows.

The Australian Signals Directorate's Essential Eight treats this as basic hygiene: operating systems and applications that vendors no longer support should be removed or replaced. Cyber insurers increasingly ask the same question on renewal forms, and "we've still got a few of those" is not the answer they're hoping for.

1. Internet Explorer

Microsoft retired Internet Explorer 11 on 15 June 2022 and then switched it off for good on most Windows 10 machines with an Edge update in February 2023. If someone in your office still says "that site only works in IE", the answer is IE mode in Microsoft Edge, which renders old intranet pages using the legacy engine without keeping the whole old browser around. Better still, ask the vendor of that site when they plan to join the present. We've covered the details in what IE's retirement means for you.

2. Adobe Flash Player

Adobe ended support for Flash at the end of 2020 and has blocked Flash content from running since January 2021. Modern browsers won't load it at all. The risk now is the leftover installer or standalone player on an old PC, usually kept for a training module or an old piece of equipment software. Uninstall it. Anything that genuinely needs Flash in 2026 needs replacing, not preserving.

3. Windows 10

This is the big one. Windows 10 reached end of support on 14 October 2025. Machines still running it get no security updates unless they're enrolled in Microsoft's paid Extended Security Updates program, which is a stopgap, not a plan. Most PCs bought from about 2018 onwards can run Windows 11 for free; the ones that can't (usually because of an older processor or no TPM 2.0 chip) are due for replacement anyway.

Do the maths on a typical small office. Ten PCs, three of them too old for Windows 11. Upgrading seven is an afternoon of scheduled work. Replacing three is a budget line. Ignoring all ten is a gamble you're taking every day. Our guide to building an IT refresh plan shows how to spread that cost so it doesn't arrive all at once.

4. Office 2016, 2019 and (very soon) 2021

Office 2016 and Office 2019 also lost support on 14 October 2025, and Microsoft offered no extended updates for them. Office 2021 follows on 13 October 2026. If you bought Office as a one-off licence in the last few years, check which version it is, because it may only have days left.

Why does this matter for "just Word and Excel"? Because Office documents are one of the most common ways malware arrives. An attachment that exploits an unpatched Office bug only needs one person to open it. Moving to Microsoft 365 keeps the apps patched automatically, which is the whole point.

5. Exchange Server 2016 and 2019

On-premises Exchange Server 2016 and 2019 reached end of support on the same October 2025 date. Email servers are about the worst possible thing to leave unpatched: they sit on the internet by design, they hold every message the business has sent, and Exchange has been the target of several large exploitation campaigns over the years. The options are Exchange Online in Microsoft 365 or Microsoft's newer subscription edition of Exchange Server. For most small businesses, moving the mailboxes to the cloud is simpler, and it's the kind of job our email and data migration team does every month.

6. Windows Server 2012, 2016 and SQL Server 2016

Windows Server 2012 and 2012 R2 lost support in October 2023, so anything still running them has been unpatched for three years. Windows Server 2016 is next, on 12 January 2027. SQL Server 2016, the database that sits underneath a lot of accounting, practice management and inventory software, reached the end of extended support on 14 July 2026.

Servers deserve special attention because they hold the shared files, the line-of-business database and often the logins for everyone. We've written a whole guide on what to do before Windows Server 2016's deadline.

7. Skype

Microsoft retired Skype in May 2025 and moved users to Teams. Skype for Business Online went even earlier. If you still have staff or customers who expect to reach you on Skype, it's time to update your email signatures and website, and set up Teams or a proper cloud phone system instead.

8. Microsoft Publisher

The newest addition. Microsoft has confirmed that Publisher is no longer available to Microsoft 365 subscribers after 1 October 2026, and perpetual versions lose support with Office 2021 on 13 October. This one isn't so much a security risk as a file-format trap: years of newsletters, flyers and price lists saved as .pub files. Open them and save them as PDF or Word documents now, while you still can, then rebuild your templates in Word, PowerPoint or a design tool.

What about older Macs?

Apple doesn't publish an end-of-support calendar the way Microsoft does. In practice, the current macOS release gets every security fix, the previous couple of releases get some, and anything older quietly stops receiving updates. A Mac that can't upgrade to a recent macOS version is in the same position as a Windows 10 PC, just without the official announcement.

How to find out what's lurking on your network

The hard part isn't knowing what's unsupported. It's knowing what you've got. Software has a way of surviving on that one PC in the back office, or a server nobody's logged into since the person who set it up left. Three quick checks:

• List every computer and its operating system version. On Windows, press Windows + R, type winver and press Enter.
• Check the installed apps in Settings → Apps → Installed apps for old Office versions, Flash, Java runtimes and anything you don't recognise.
• Ask your software vendors which server and database versions they support. Many line-of-business apps quietly drop support for old SQL Server versions before Microsoft does.

For anything more than a handful of machines, an IT audit does this properly and gives you a prioritised list rather than a vague sense of unease. A managed IT service keeps it up to date, so the next deadline doesn't sneak up on you.

Frequently asked questions

Is it safe to keep using Windows 10 in 2026?

Not without Extended Security Updates. Windows 10 support ended on 14 October 2025, so a PC that isn't enrolled in Microsoft's paid ESU program receives no security fixes. Upgrade eligible PCs to Windows 11 for free and replace the ones that can't run it.

When does Office 2021 support end?

Office 2021 and Office LTSC 2021 reach end of support on 13 October 2026. Office 2016 and Office 2019 already ended on 14 October 2025. Microsoft 365 subscriptions stay supported because they're updated continuously.

What happens when software reaches end of life?

It keeps working, but the vendor stops releasing security fixes and technical support. Any new vulnerability found after that date stays open permanently, and attackers actively look for systems running end-of-life software because the holes are known and guaranteed not to be fixed.

What can I use instead of Microsoft Publisher?

Microsoft suggests Word and PowerPoint for most Publisher jobs, such as flyers, newsletters, labels and business cards. Convert existing .pub files to PDF or Word format before you lose access, then rebuild templates in the new app.

Local IT and cyber security support across NSW

Chewing IT runs managed IT and cyber security for small and mid-sized businesses from our Wyong and Hornsby offices, covering the Central Coast, Newcastle, Lake Macquarie and Hornsby.

Not sure what's out of support in your office? Book an IT audit and we'll give you a plain-English list of what to replace, and in what order.