Keeping Windows and macOS alive past their sell-by date

Practical steps to make an aging operating system usable into 2026

Part 1 You can switch to running mostly FOSS without switching to Linux. First, though, give your OS a bit of TLC. We'll come back to what to do next in part two.

Most computers run the OS they came installed with until they're scrapped… because most non-specialists would prefer to just buy a whole new computer than deal with trying to change their OS. The majority of desktop and laptop computer users have never seen or used anything but Windows, and of the remainder, most use Macs – and the same applies. Most Macs will never run anything but their original copy of macOS.

If you're happy with that, it's OK. Switching OS is a big ask, especially if you're happy with Windows or macOS. You can still benefit from the world of FOSS – for instance, if you're tired of paying for applications, or worse still, app subscriptions, you have plenty of options. This is especially true if you're using an older version of your OS and the vendor isn't sending you updates any more.

Freshen up that tired old OS

If you can, think about wiping and reinstalling. This applies equally to PCs and Macs.

Firstly, if you've got a really old OS and you're willing and able to reinstall it, that is a good move. A clean installation will be faster.

Before you start, back up all your stuff. Ideally, make at least two complete backups of all your files, and this includes the data files of apps that store and manage data, such as email clients. Buy some USB keys, a couple of small ones and a couple of the biggest ones you can afford. Using the OS's built-in tools, do a full backup of the whole computer onto one of the big keys. As well as this backup, on the second big key, manually copy all your files. Look for where things like email clients store their data – Google is still helpful for stuff like this – and include those too. If there's room, duplicate the whole lot: the more copies the better. Even if you decide not to go ahead, having this kept somewhere safe is a great safety net.

Also, max out your old box. We recommend fitting as much memory as your machine will take – secondhand RAM is fine, it doesn't wear out, and your local small computer store should help. If the machine has a spinning hard disk drive, get an SSD, and put the old disk into an external USB caddy as a backup drive.

Next, you need a fresh OS installer.

Here, Mac users have it easy: Apple has an official "How to download and install macOS" page, with links to all versions from 10.13 to the current Tahoe. And of course there are no keys, serial numbers, activation or anything.

We recommend running the latest OS version that your Mac can handle. Even High Sierra is still usable. As we wrote when the latest Firefox ESR appeared in June, the ESR release before last, Firefox 115, is still getting security updates on macOS 10.13. We've also previously covered alternative browsers for macOS versions even older than High Sierra — all is not lost.

There's a built-in command to create a bootable USB installer inside the macOS installer application, but if that sounds too intimidating, there are third-party point-and-click apps such as MacDaddy's Install Disk Creator or the open source TINU.

If the latest OS your Mac can run is just a bit too old to be practical, then OCLP can help. OpenCore Legacy Patcher, to give it its full name, will let you install a newer macOS than Apple officially supports. For now, it tops out at Sequoia, macOS 15. The team is working on Tahoe support, but don't even try it for now. If you have a well-specced older Mac that's still adequate for your needs, it's worth a shot, but have multiple backups and be prepared to just reinstall the latest supported version, restore your backup, and get on with life.

On PC, life is a bit more complicated, as ever.

Firstly, and we expect some will disagree here, we suggest that you avoid the vendor's own reinstallation disks. A lot of PC vendors benefit from additional income derived from bundling bloatware with their new machines. If you use the vendor's own reinstallation media, you reinstall that bloat too. Secondly, the result will probably be very dated and so need tons of updates, which will take hours.

Before you begin, you should grab a copy of Snappy Driver Installer Origin and put it on a clean, empty USB key. Then run it, directly on the new key, and tell it to download all its driver packs. SDIO is the only driver-installer tool we trust and recommend. Don't pay for any alternative: indeed, we suggest you avoid anything else. SDIO is big – it takes quite a few gigabytes with all the driver packs or more – and takes a long time to download all the drivers, but it does the job. We've found it helpful from Windows XP all the way up to Windows 10.

Next, get a clean version of Windows. If you have the license key, you're all set. If you don't have your license key, then you can extract it from the running copy of Windows with Nirsoft ProduKey.

Using the key for older versions, you can download a clean copy from Microsoft itself. It has download pages for Windows 10 ISO files and Windows 11 ones too.

However, if you are willing to change versions, we suggest switching to Windows 10 LTSC. As we explained back in August, the Windows 10 Enterprise LTSC 2021 edition will get updates until 2027, and if you don't mind using US English, it'll last until 2032. As an added bonus, it's remarkably uncluttered – it doesn't even have the Windows Store, and so no "Modern" applications. Aside from Notepad, there's very little there at all, which is just how we like it.

As we have written before, if you just want to write a Windows ISO to a USB key, then Rufus can help, but Ventoy is quicker and more flexible.

Keeping an old OS useful

Some of the hints for older, unsupported OSes apply equally to both Mac and Windows. Both come with an assortment of bundled apps and tools – accessories is a handy catch-all term – and once the OS isn't getting updated, then the accessories aren't either.

That may not matter. For example, there's very little risk in using an outdated text editor, although the vendors are working hard to make it more risky by embedding pointless bloat such as LLM-bot based "AI assistants." The thing to consider is an extension of such a universal rule that it's got a name – Zawinski's Law:

Every program attempts to expand until it can read mail. Those programs which cannot so expand are replaced by ones which can.

The thing to consider here is whether the handy accessory talks to the internet. If it doesn't, then it's fairly safe. If it does, then it's a potential risk, and think about replacing it – ideally with some FOSS tool that's still maintained. Chat or messaging clients, email programs, streaming music players – these have to talk to the internet to work, and so bundled and built-in ones are a risk. To keep using an older OS, look for replacements for any accessory that talks to the internet, and replace it. We will return to this in the second part of this short series.

Don't neglect the housekeeping

Of course it doesn't need to be a clean, empty copy of Windows. It will work even on a well-used installation, and once you're content with your replacement apps, you can uninstall anything you no longer need. We've given some tips on doing some housekeeping on Windows, both before dual-booting and then again when discussing running Windows 7 nowadays.

In brief: run Windows Update. Update everything. Reboot, and do it again, and keep doing that until there are no more updates. Then run Disk Cleanup, tick all the boxes, let it work, then do the same again but tick the "Clean up system files" button first. Reboot, and do it again. Finally, right-click the Start button and click the entry for Command Prompt (Admin) or words to that effect, type CHKDSK C: /F, answer "Y" for "Yes" and then reboot, to fix any disk corruption.

If you've already upgraded to Windows 11 and regret it, you may be able to downgrade again – even if the built-in uninstaller isn't available. We haven't tried this yet, but TeknixStuff's UpDownTool claims to be able to reinstall Windows 10 LTSC on top of Windows 11.

If you don't want to switch to LTSC, there are some tools to help cut the crud from ordinary retail Windows a bit. In the past, we have used O&O AppBuster and O&O ShutUp with considerable success.

What we recommend avoiding, though, are third-party cleanup tools, especially "registry cleaners." These can do more harm than good.

Stay tuned for our next exciting episode

Once you've either got a clean install of your unfashionable but pragmatic OS, then the next question is what you install and run on it. We explore that in part two. ®