File Format & Compatibility

How to Fix Microsoft 365 Not Opening Older Files After Update

Emma Brown Oct 14, 2026 870 views

Question details

The user is unable to open older document files after updating Microsoft 365, with the system failing to recognize the default application.

How to Fix Microsoft 365 Not Opening Older Files After an Update

Product: Microsoft 365
Device & OS: Windows
Scenario: Trying to double-click and open older files from local storage or OneDrive after completing a Microsoft 365 update.
Observed behavior: Windows loses the file association, asks which app should open the files, and incorrectly suggests searching the Microsoft Store.

Before you start

Ensure that your Microsoft 365 subscription is active and that the recent update was installed completely without any error messages.

Solution 1Recommended

Manually Re-associate the File with Microsoft 365

Set your Microsoft 365 applications as the default programs for older file types to prevent Windows from searching the Store.

Major Microsoft 365 updates can sometimes reset default file associations in Windows. Manually pointing Windows to the correct application will permanently resolve this prompt.

Right-click the older file

Locate the file you are trying to open, right-click on it, and select 'Open with' from the context menu.

Choose another app

Click on 'Choose another app' to expand the list of available programs on your computer.

Select the correct Office application

Select Word, Excel, or PowerPoint depending on the file type. Check the box that says 'Always use this app to open files' and click OK.

Manually Re-associate the File with Microsoft 365

File Association Restored: All files sharing this older extension will now automatically open in the designated Microsoft 365 app.

Solution 2

Open Files Using the In-App Browse Feature

Bypass Windows file association errors by opening the older documents directly from within the Microsoft 365 application.

Solution 3

Download OneDrive Files Locally

If your files are stored in OneDrive, they may be experiencing synchronization issues preventing them from opening.

Free Microsoft Office alternative

Use WPS Office to Open All Your Older Files Hassle-Free

Avoid Microsoft 365 update bugs and file association errors entirely. WPS Office is a free, lightweight alternative that seamlessly opens older document formats with high compatibility and a familiar interface.

1. Download and Install WPS Office: Get the free installation package from the official WPS website and complete the quick setup.
2. Set as Default Program: During the installation process, allow WPS Office to be set as the default application for your documents.
3. Open Your Files Directly: Double-click your older files, and they will seamlessly open in WPS Office without any Microsoft Store prompts.

Highly compatible with all older and newer Microsoft Office formats (DOC, DOCX, XLS, XLSX)Lightweight installation without disruptive forced updates that break file associationsFamiliar user interface ensuring a seamless migration with zero learning curve

microsoft office alternative - wps office

Frequently Asked Questions

Why is Windows asking me to search the Microsoft Store when opening older files?

This usually happens when a Microsoft 365 update resets or breaks the default file associations in Windows. The operating system momentarily forgets which program is supposed to open older extensions like .doc or .xls.

Can I still open older .doc or .xls files in Microsoft 365?

Yes, Microsoft 365 still supports older formats. You simply need to re-establish the file association via the 'Open with' menu, or open the files directly using the File > Open > Browse option inside Word or Excel.

What should I do if my OneDrive files refuse to open after the update?

If OneDrive files are affected, they might not be fully synchronized to your desktop. Right-click the problematic file in File Explorer and select 'Always keep on this device' to download a local copy before attempting to open it again.

Document & File Issues