Microsoft has resurfaced a critical deadline that puts a ticking clock on any PC running the Microsoft Store version of its Office apps. As of October 2025, those Store-installed Word, Excel, and PowerPoint installations stopped receiving feature updates—and after December 2026, security patches will halt entirely. If you installed Office from the Microsoft Store and never migrated, you’re on borrowed time.

This isn’t about a new version of Office or a forced repurchase. It’s a behind-the-scenes packaging switch that matters more than it sounds, because the way Office updates, integrates with Windows, and stays secure all hinge on which installation type you’re running. The fix is straightforward, but only if you know to check.

The Silent Retirement: What’s Ending and When

Most users don’t think about how Office got onto their PC. You might have grabbed it from the Microsoft Store years ago, or maybe it came preinstalled. Either way, if a Microsoft 365 app’s Account screen says “Microsoft Store” under “About,” you’re on the losing side of this lifecycle move. Microsoft confirmed in a support document first reported by Windows Latest that it’s deprecating the Store installation type of Microsoft 365 Apps.

The timeline is concrete:
- Feature updates ended in October 2025. No new capabilities will arrive.
- Security updates continue only until December 2026. After that, the Store version becomes a frozen, vulnerable relic.

The apps won’t suddenly vanish from your taskbar, but running them past the cutoff will be risky—and for businesses, likely a compliance violation.

Why the Store Version Lost Its Place in the Office Lineup

Microsoft spent years pushing the Store as a modern, sandboxed distribution channel tethered to Windows Update. For lightweight apps, that model works. But Office is a sprawling productivity platform that enterprises need to manage with surgical precision: update channels, shared device activation, Group Policy controls, and integration with tools like Microsoft Intune and Configuration Manager.

Click-to-Run, the alternative installation technology, is built for that reality. It streams and patches Office directly from Microsoft’s content delivery network, independent of Windows Update. It supports multiple update cadences—monthly, semi-annual—and lets administrators pin specific versions. The Store version, by contrast, never supported XML configuration files, multi-user environments, or the granular management that IT departments demand.

“Support for the Microsoft Store installation type of Microsoft 365 Apps is ending,” Microsoft’s advisory states bluntly. The reason is clear: Office outgrew the Store’s consumer-first plumbing.

Copilot’s Shadow: Why This Change Is Happening Now

There’s an unspoken driver behind the timeline. Microsoft 365 is increasingly infused with cloud-powered AI features—Copilot in Word, Excel, and PowerPoint—that require rapid, reliable delivery of new code. Click-to-Run enables that velocity; the Store’s dependency on Windows Update can bottleneck feature rollouts by weeks or months. As Microsoft pushes more intelligent, context-aware tools into Office, a servicing model that lags behind becomes a strategic liability.

This shift also aligns with Microsoft’s broader move to treat Office not as a static product but as a constantly evolving service. Click-to-Run is the pipeline, and the Store version was a dead end.

Are You Affected? A 10-Second Check

Determining your installation type takes less than half a minute:
1. Open any Microsoft 365 app—Word, Excel, or Outlook.
2. Click File > Account.
3. Look beside the “About” button. You’ll see either “Click-to-Run” or “Microsoft Store.”

If you see Click-to-Run, breathe easy—no action needed. If you see Microsoft Store, the clock is ticking.

How to Migrate: Step by Step

Microsoft built a clean migration path. The process removes the Store installation and reinstalls Office using Click-to-Run, carrying over your license and settings automatically. No new subscription is required.

For a single PC:
1. Save all work and close every Office app.
2. Go to Microsoft’s official Microsoft 365 installer page and sign in with your Microsoft account.
3. Download and run the Office Deployment Tool (the regular installer works too).
4. The tool detects the Store version, uninstalls it, and installs Click-to-Run in one go. The process may take a few minutes longer than a standard repair because it’s doing double duty.
5. After the install completes, open an Office app and confirm the About section now reads “Click-to-Run.”

For IT administrators:
Use the Office Deployment Tool with your usual deployment infrastructure (Intune, Configuration Manager, or Group Policy). Include the <RemoveMSI> and <Remove> elements to force removal of the Store version and replace it with Click-to-Run. Microsoft’s learn.microsoft.com documentation spells out the XML configuration. The managed approach can silently migrate entire fleets without user interaction.

What Happens If You Do Nothing?

After December 2026, no more security patches. Office has been a favorite vector for malicious documents, macro-based attacks, and embedded content exploits for decades. Running an unsupported installation type after the cutoff is like leaving a known crack in your digital front door. For home users, that means heightened risk from phishing attachments. For organizations, it can trigger audit failures, insurance complications, and non-compliance with data protection regulations.

Feature stagnation is a nuisance; security stagnation is a danger.

The Store’s Waning Role in Windows’ Future

This sunset says as much about the Microsoft Store as it does about Office. The Store was meant to tame Windows’ wild west of software installation, but even Microsoft’s own flagship productivity suite couldn’t live within those walls. Click-to-Run won because Office is infrastructure, not an app you casually download between Netflix and a calculator widget. The irony is sharp: at a time when Microsoft is championing native Windows development with WinUI3, its most important desktop software is walking away from the Store packaging model.

The Store will survive for simpler apps, but this move cements a truth: complex, enterprise-grade software needs deployment plumbing the Store can’t provide.

What to Watch Next

Expect Microsoft to continue consolidating Office servicing lanes. The end of the Store installation type mirrors the retirement of legacy MSI-based installers and Office Online Server. The goal is a single, manageable Click-to-Run backbone that can keep pace with AI innovation. For users, the migration is a one-time inconvenience. For admins, it’s a cleanup task that should be tackled well before the December 2026 holiday change freeze. The deadliest threat here isn’t technical—it’s forgetting to look.