When your operating system reaches end of life.
Microsoft and Apple stop patching old operating systems on a published schedule. After that date, new security holes stay open on every machine still running that version, and cyber insurers and the Privacy Act treat it as a control failure. The dates and the upgrade steps are below.
Three things stop on the date.
Microsoft and Apple publish the date for each version, and the same three things stop on it.
Where the deadlines fall.
Microsoft publishes fixed end-of-support dates per version. Apple supports the current and two prior major macOS versions, with security updates rolling forward as new versions ship.
A compatibility bypass installs Windows 11 unsupported.
Tools like Rufus, registry workarounds and modified install media will put Windows 11 on hardware that fails Microsoft's compatibility check. We do not do this for clients, for the three reasons below.
Start with a list of every machine and its version.
Tag every workstation, laptop and server by OS version, edition and patch level.
The list usually turns up machines nobody had counted, and those are the ones an upgrade plan misses.
Not every Windows 10 machine can run Windows 11.
Windows 11 requires TPM 2.0, UEFI with Secure Boot, an 8th-generation Intel CPU (or newer AMD equivalent), 64 GB of storage, and 4 GB of RAM as minimums.
Devices that miss the bar need replacing rather than upgrading in place. We run the compatibility check as part of every Evaluation.
Pilot with a small group, then expand.
Migrate a small group of users first, enough to flush out line-of-business compatibility issues without putting the whole office at risk.
Once the pilot is stable, roll out by team or floor in stages over a quarter. We do the planning, the imaging, and the after-hours cutover.
Allow eighteen months for a fleet upgrade.
Hardware lead times lengthen in the months before a Microsoft end-of-support date because demand peaks then.
Cyber insurance renewals can exclude unsupported operating systems, and the Privacy Act and industry compliance regimes treat them as a control failure.
Browsers reach end of support too.
Chrome, Edge, Firefox and Safari update themselves by default. The problems arise when something stops the updater, or when the operating system is too old for the current browser version.
Plan the upgrade before the date.
We check hardware compatibility as part of every IT review.