Microsolve Business IT Insights

Microsoft Product End-of-Support - What Organisations Must Do Now

Written by Dale Jenkins | 18 September 2025 10:30:00 PM

On October 14, 2025, Microsoft ends support for multiple critical products simultaneously. This date represents one of the most significant technology transitions in recent years, affecting millions of organisations worldwide.

The Class of 2025 (Product Retirements)

Microsoft's end-of-support date affects a comprehensive range of business-critical applications. 

  • Windows 10 (all editions) - Home, Pro, Enterprise, Education, and IoT Enterprise - will no longer receive security updates.
  • Office 2016 and 2019 suites, including applications like Word, Excel, Outlook, PowerPoint, and associated products like Visio and Project, lose support and updates.
  • Exchange Server 2016 and 2019 no further updates, security patches or vendor support
  • Skype for Business Server 2015 and 2019 the end of the Skype platform - organisations need to migrate to Teams
  • Visual Studio 2015 no further updates, security patches or vendor support.

This collective retirement creates an unprecedented challenge for IT departments, Service Providers and Consultants tasked with managing integrated Microsoft environments.

Immediate Security Implications?

In short, Yes.

After October 14, 2025, affected products will no longer receive security patches, bug fixes, or technical support from Microsoft. This creates POTENTIAL immediate vulnerabilities that cybercriminals can exploit, knowing these flaws will never be patched. Recent zero-day vulnerabilities discovered in Office 2016 demonstrate that this is a clear and ongoing security risk.

Organisations continuing to use such unsupported software WILL face exposure to malware, ransomware and the associated data breaches. Each unpatched vulnerability becomes a permanent entry point for attackers. 

Compliance frameworks like ISO 27001 and the ACSC Essential Eight as well as privacy regulations increasingly require organisations to maintain supported software - choosing to ignore the Microsoft "End of Support" date is the same as choosing to ignore compliance regulations - plain and simple.

Your Business Continuity Risks

Beyond the clear security concerns, organisations will face significant and ever increasing operational disruptions. As an example, since Microsoft 365 integration support with older Office versions was discontinued in 2023, many users have experienced the impact of no email in Outlook and having to revert to Webmail access.

Line-of-business applications that integrate with Office products will experience similar failures. ERP systems, CRM platforms, and financial applications often rely on Excel integration or (Legacy!) Outlook plugins for critical workflows. As these older Office versions fall further behind cloud service standards, essential business processes will break without warning and cause un-planned impacts on significant portions of your workforce.

The simultaneous retirement of Windows 10 and Office compounds these compatibility issues - some new Windows 11 features and security protocols may not work properly with legacy Office installations, forcing organisations into reactive troubleshooting rather than planned transitions (and the frustration and diversion from critical projects that this causes).

The Financial Impact

Lets be really Clear:

The cost of inaction far exceeds the investment in planned upgrades.

For Windows 10 Extended Security Updates, business pricing starts at US$61 per device for the first year, doubling to US$122 in year two, and reaching US$244 in year three - that's a total of US$427 per device over three years! While this WILL give you access to CRITICAL security upgrades, it WON'T protect you from software compatibility issues or extend the life of older office applications.

Migration costs to Microsoft 365 typically cost between $50 & $250 per user depending on complexity and mailbox count. While this is a substantial upfront cost, these investments provide long-term value through improved security, collaboration capabilities, and reduced maintenance overhead. Delaying this will increase the chance of needing to do an emergency migration, with costs that are likely some 40-60% higher due to compressed timelines, limited planning options and increased risk of unforeseen impacts!

The hidden costs of remaining on unsupported software include increased IT support time, potential compliance fines, cyber insurance premium increases, and business disruption from security incidents. A single ransomware attack can cost organisations hundreds of thousands of dollars in recovery efforts, legal fees, and lost productivity.

Our Recommendations!

Small organisations (under 50 users) prioritise immediate assessment and pilot testing. Begin with a small group of users to validate new software compatibility with existing workflows. Microsoft 365 Business Basic provides cloud-based Office applications with essential security updates. Consider simultaneous Windows 11 upgrades to maximise compatibility and minimise disruption.

Medium organisations (50-250 users) require phased deployment strategies. Start with pilot groups in less critical departments while maintaining parallel systems during transition. Microsoft 365 Business Premium includes advanced security features essential for growing businesses. Plan for 3-6 month migration timelines to allow proper testing and training.

Large organisations (250+ users) need comprehensive enterprise planning. Leverage Microsoft FastTrack services for eligible subscriptions and consider Microsoft 365 E3 or E5 licensing for advanced compliance and security features. Implement staged rollouts by department or location, maintaining detailed compatibility testing for line-of-business applications. Budget for extensive change management and user training programmes.

Migration Pathways

Organisations have three primary upgrade paths:

  1. Microsoft 365 subscription provides always-current Office applications with cloud integration, AI-powered features, and cross-device compatibility. This option suits organisations embracing cloud-first strategies and requiring regular feature updates.
  2. Perpetual licensing through Office 2021 (supported until October 2026) or Office LTSC 2024 (supported until October 2029) serves organisations requiring traditional ownership models or air-gapped environments. These versions receive security updates but lack cloud enhancements and collaborative features.
  3. Hybrid approaches combining cloud services with on-premises infrastructure offer flexibility for complex environments. This might include Exchange Online for email while maintaining local file servers, or Microsoft 365 Apps with SharePoint Server for document management.

Implementation Timeline

Microsoft first announced the October 14 2025 deadline back in June 2022, to give users ample time to prepare for the end of support and transition to a more supported operating system.

For those with their heads buried in the sand, there is STILL TIME to effectively handle this. Here are our top three tips to prepare for the fast-approaching deadline. 

  • Phase 1 should focus on comprehensive auditing of current installations, compatibility testing with critical applications, and pilot deployments with early adopter groups.
  • Phase 2 involves broader rollouts to non-critical departments, staff training programmes, and refinement of deployment procedures based on pilot feedback. This period allows organisations to identify and resolve integration issues before affecting business-critical operations.
  • Phase 3 completes migration of remaining users, decommissions legacy software, and validates that all systems operate correctly. This final phase includes comprehensive testing of disaster recovery procedures and confirmation that compliance requirements are met.

Risk Mitigation Strategies

Successful transitions require proactive risk management. 

  • Backup critical data including PST files, templates, macros, and custom configurations before beginning migrations. Document existing integrations and custom applications that depend on legacy Office versions.
  • Test extensively in isolated environments before production deployment. Create validation checklists covering document formatting, email rules, macro functionality, and third-party integrations. Engage software vendors early to confirm compatibility with newer Office versions.
  • Prepare contingency plans for critical applications that may not immediately support newer Office versions. This might include temporary workarounds, alternative software solutions, or delayed migrations for specific departments while solutions are developed.

Professional Support Recommendations

The complexity of simultaneous Windows and Office transitions often exceeds internal IT capabilities. Engaging experienced migration specialists can prevent costly mistakes and ensure smooth transitions. Professional services typically include compatibility assessment, migration planning, user training, and post-deployment support.

Choose partners with demonstrated Microsoft expertise and references from similar organisations. Avoid providers offering unusually low prices without comprehensive service inclusion. Successful migrations require thorough planning, testing, and change management support.

The October 14, 2025 deadline represents a critical inflection point for organisational technology strategy. Proactive planning and early implementation will ensure smooth transitions while maintaining business continuity and security. Organisations that delay face increasing costs, security risks, and operational disruptions that could have been avoided through timely action.