Hold on to your keyboards, Windows administrators, because 2025 isn’t just shaping up to be the year Microsoft hypes up Windows 11; it’s also a year of farewells—a number of features and technologies across Microsoft 365 (M365), Windows, and related services are heading for the great tech graveyard. If you’re still holding onto legacy tools and apps, it’s time to brace yourself for all these changes.
Microsoft has already flagged off several retirements well in advance, but the sheer volume of them set for 2025 could make even the most seasoned IT admins break into a cold sweat. From the deprecation of old-school Exchange Online tokens to the final demise of "classic" Teams, here’s a detailed breakdown of what’s going away, when it’s happening, and what it means for your enterprise and personal systems.
But does all this mean smoother sailing ahead? Not necessarily, as many legacy systems don’t just disappear overnight. The year ahead will likely be a whirlwind of troubleshooting, updating, and adapting—especially for enterprises heavily rooted in the old Microsoft ecosystem. It’s a reminder that technology waits for no one.
So administrators, brace yourselves. As the classic idiom goes: Gone are the days of the calm desktop OS. 2025 belongs to the relentless march forward. Let us know your thoughts and preparations in the comments below!
Source: The Register Microsoft preps for a year of enterprise-impacting M365 retirements
Microsoft has already flagged off several retirements well in advance, but the sheer volume of them set for 2025 could make even the most seasoned IT admins break into a cold sweat. From the deprecation of old-school Exchange Online tokens to the final demise of "classic" Teams, here’s a detailed breakdown of what’s going away, when it’s happening, and what it means for your enterprise and personal systems.
What We’re Losing in 2025: A Month-by-Month Breakdown
February: Early-Bird Challenges
The year's first wave of retirements begins in February with several changes aimed at Exchange Online and Microsoft’s email ecosystem:- Legacy Exchange Online Tokens:
- These tokens, which keep older Outlook add-ins running smoothly, will no longer be supported. Microsoft has allowed admins to buy some extra time by re-enabling them via PowerShell, but this grace period ends in June, and the entire system will shut off by October.
- Impact: Many enterprise workflows that rely on older Outlook web add-ins (those built using the Office.js APIs) could see significant disruption. Fortunately, COM-based add-ins likely won’t be affected.
- RBAC Application Impersonation Role:
- The once-popular Role-Based Access Control (RBAC) feature that lets certain apps impersonate users and interact with multiple mailboxes is being retired.
- Apps will need to be registered with Microsoft Entra (formerly Azure AD) as part of the company’s push for more robust identity management.
March: PowerShell Modules Get Axed
- Azure AD and MSOnline PowerShell Modules are dropping off the support list. If your scripts and management processes rely on these legacy tools, it’s time to migrate to the modern Microsoft Graph PowerShell SDK.
April: Curtains for Domain-Isolated Web Parts in SharePoint
This one is for SharePoint administrators and developers: the domain-isolated web parts feature will start its deactivation journey. It will first stop being available for new tenants in April 2025 and be completely removed for existing tenants by April 2026.- What Were Domain-Isolated Web Parts?
- A developer feature ensuring web parts ran in separate domains for better isolation and security. But performance wasn’t ideal, and Microsoft is redirecting developers toward modern alternatives.
July: Good-Bye to Classic Teams
Microsoft Teams’ "classic" desktop app is finally headed to the chopping block. Initially dropped out of support in 2024, the application will stop functioning entirely on July 1, 2025.- Why It Matters:
- If your users aren’t already on Microsoft’s new Teams desktop client (sometimes dubbed "Teams 2.0"), it’s time to make the switch. The updated app promises better performance and features but may also require additional training for end users.
September: Farewell to Basic Authentication
In yet another Exchange Online-related move, basic authentication for client submission will end. This step is part of Microsoft’s broader mission to phase out insecure login methods in favor of modern authentication protocols like OAuth 2.0.October: The Big Wave of Retirements
- Windows 10: The inevitable is finally here—support for most editions of Windows 10 ends, pushing enterprises and individuals toward Windows 11.
- Microsoft Office 2016 & 2019 support ends: Prepare to bid farewell to these widely-used suites. Enterprises relying on older Office editions will need to upgrade to Microsoft 365 or Office LTSC.
- Microsoft OneNote for Windows 10: This app, pre-installed in Windows 10, will no longer be supported. The standalone OneNote desktop app remains available.
- M365 Apps on Windows Server 2016/2019: Say goodbye to the ability to install Microsoft 365 Apps on these versions of Windows Server.
December: The Quiet Exit of Viva Goals
- The short-lived Viva Goals service will officially shut down by the end of the year. While its direct impact may be minimal (given its relatively niche adoption), it signals yet another area where Microsoft is pruning underperforming initiatives.
End of 2025: Office 365 Connectors in Teams
Despite massive pushback in 2024, Microsoft still plans to go through with killing Office 365 Connectors in Teams. These connectors (along with webhooks) allowed users to automate workflows and integrate notifications into Teams channels. Microsoft’s official alternative? Power Automate, a more flexible but also more complex service.What’s Driving the Wave of Retirements?
Microsoft isn’t doing this just for fun—it’s all about modernizing its ecosystem, tightening security, and prioritizing features that align with its future goals. Here’s the underlying reasoning:- Security: Legacy tokens and basic authentication are inherently less secure than today’s modern authentication methods.
- Performance: Features like domain-isolated web parts or the classic Teams desktop app may not align with Microsoft’s efficiency goals.
- Consistency: By encouraging migrations to Windows 11, modern Teams, and Microsoft Graph APIs, Microsoft is standardizing its ecosystem to reduce long-term complexity.
What Should You Do Now?
For IT Admins:
- Audit Dependencies: Inventory all systems and workflows relying on the retiring features or legacy apps like Office 2016.
- Plan Ahead: Migrate away from deprecated PowerShell modules and legacy tokens well before their final cut-off dates.
- Train Your Users: Whether it’s transitioning to Windows 11, Teams 2.0, or modern authentication, your users will need guidance and support.
For Individual Users:
- Upgrade Early: If you’re still running Windows 10 on your personal devices, it’s best to upgrade to Windows 11 before October 2025.
- Switch Apps: Move to newer cloud-based Office tools to ensure ongoing support and security updates.
The Broader Implications: Focus Shifts to Windows 11 and Beyond
While all eyes might be on Windows 11 as Microsoft continues to push it hard in 2025, the reality is that enterprises may struggle to embrace innovation while grappling with this wave of retirements. From freeing up resources tied to legacy systems to enforcing tighter security protocols, these moves align with Microsoft’s future-proofing strategy.But does all this mean smoother sailing ahead? Not necessarily, as many legacy systems don’t just disappear overnight. The year ahead will likely be a whirlwind of troubleshooting, updating, and adapting—especially for enterprises heavily rooted in the old Microsoft ecosystem. It’s a reminder that technology waits for no one.
So administrators, brace yourselves. As the classic idiom goes: Gone are the days of the calm desktop OS. 2025 belongs to the relentless march forward. Let us know your thoughts and preparations in the comments below!
Source: The Register Microsoft preps for a year of enterprise-impacting M365 retirements
