Windows 10 and Microsoft 365 Deadlines: What Businesses Must Know

Windows 10 reached the end of its standard support lifecycle on 14 October 2025, but many South African businesses still use it every day.

A Windows 10 computer does not suddenly stop working after support ends. That is precisely why the risk can be easy to ignore. The machine may continue opening email, browsing the internet and running business software while gradually falling behind current security and compatibility requirements.

Businesses now need to distinguish between three separate issues: Windows security support, Extended Security Updates and Microsoft 365 application support.

What happened to normal Windows 10 support?

Microsoft no longer provides ordinary free security updates, feature improvements or technical support for standard Windows 10 installations.

Eligible devices can receive Extended Security Updates, commonly called ESU, for a limited period. ESU can be useful when a business needs additional time to replace specialist hardware or test important software.

It should be treated as a transition measure—not as a permanent strategy for keeping ageing computers indefinitely.

Microsoft 365 has a different timetable

Microsoft has continued providing security updates for Microsoft 365 Apps running on Windows 10 for a transitional period.

According to Microsoft’s current lifecycle guidance, Version 2608 is the final Microsoft 365 Apps feature version for Windows 10. Devices remaining on that operating system can continue receiving security updates for that version until 10 October 2028.

This does not restore full Windows 10 support. It means the Office applications have their own temporary security-update arrangement while the underlying operating system remains outside normal support unless separately covered by ESU.

Businesses should therefore avoid interpreting “Office still receives updates” as “the computer is fully supported.”

Should you upgrade or replace the computer?

Not every Windows 10 PC needs to be discarded.

A device may support Windows 11 after firmware settings, TPM or Secure Boot configuration has been corrected. In other cases, the processor or security hardware may not meet Microsoft’s requirements.

A proper assessment should check:

• Processor and Windows 11 compatibility
• TPM version and status
• Secure Boot capability
• Available RAM and storage
• SSD health
• BIOS or firmware updates
• BitLocker recovery-key availability
• Application and printer compatibility
• Age and physical condition of the device

A technically compatible PC may still be a poor upgrade candidate if its storage is failing, battery is unusable or performance no longer meets the user’s needs. Conversely, a good-quality business laptop with adequate hardware may need only configuration, an SSD or additional memory.

Avoid unsupported upgrade shortcuts

Various online methods can install Windows 11 on unsupported computers. They may work, but a business should understand the consequences before relying on them.

Unsupported installations can introduce uncertainty around future updates, drivers and vendor support. That may be acceptable for a non-critical personal device, but it is a questionable foundation for payroll, accounting, customer service or regulated information.

Build a controlled replacement plan

Businesses should inventory their computers and classify them into four groups:

1. Ready for a normal Windows 11 upgrade
2. Upgradeable after configuration or hardware improvements
3. Temporarily retained with ESU
4. Due for replacement

This prevents emergency purchasing and allows replacements to be budgeted by business priority.

RandTech IT provides Windows compatibility assessments, upgrades, data migration and replacement-device planning for South African SMEs. If your business still has Windows 10 computers, now is the time to establish which machines can be upgraded safely and which have reached the end of their practical life.

Sources: Microsoft’s Windows 10 lifecycle page and Microsoft 365 Apps support guidance