Is Microsoft 365 Having 26 25H2 Windows Problems? Here Is the Fix

If your workflow is blocked, confirm the account and app context, then follow the ordered fixes below.

Problem Description: 26 25H2 Windows Update

The 1/9/26 25H2 Windows Update has disabled usage of all of Microsoft Excel 97 Worksheets on my laptop. I have tried changing settings in Protected View, Add Ins, File Block Settings. I have tried changing ext of files using a website to .xlsx files. I have ran my Anti Virus. HELP! I don't know why this change would have been made. I need these files to do my job!!! --- **Moved from: <****Microsoft 365 and Office | Excel | For business | Windows****>**

Quick Answer for Excel Won't Complete Task

Open Excel, go to File > Options > Trust Center > Trust Center Settings > File Block Settings, and uncheck the boxes for file types you want to open, such as Excel 97 Worksheets.

Likely Causes Behind Common File Format Triggers

• The Microsoft account or license context may not match the purchase or device.

• Cached credentials, outdated builds, or damaged local components can trigger file format & compatibility.

• A file-specific corruption or add-in conflict can mimic a broader application failure.

Recommended Solution: Fixing File Format Step by Step

When to use this: Apply these steps when the symptoms match and you can access the relevant Microsoft account or administrator.

1. If this does not resolve the issue, modify the registry to enable these files.

2. For Excel 2007, use a registry script setting 'BinaryFiles' to 0 under HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\12.0\Excel\Security\FileOpenBlock.

3. For other versions, adjust the path accordingly.

Alternative Solutions for Broader File Format Workarounds

1. Retry the Microsoft-side steps after restarting the app and device.

2. Test the same action in a private browser session or a new blank file to isolate account vs file issues.

3. Capture exact error text and screenshots before contacting Microsoft Support or your administrator.

Working with WPS Office: Using WPS While Excel Is Unavailable

WPS Office cannot replace Microsoft account, activation, or cloud fixes for this scenario. It remains one of the best free Microsoft Office-compatible alternatives for opening and editing local files.

1. Download and install WPS Office from the official website.

2. Open local Word, Excel, PowerPoint, or PDF files in the matching WPS app.

3. Save a working copy locally while Microsoft-side issues are resolved.

4. Return to Microsoft Office after the primary fix succeeds.

If you need a practical local workspace in the meantime, try WPS Office.

Prevention Tips for Avoiding Repeat File Format

• Keep one primary Microsoft account for subscriptions and Office sign-in.

• Install updates for Office and Windows before retrying failed workflows.

• Back up important files before repair, reset, or reinstall actions.

• Work on copies and keep version history enabled when available.

FAQs About 26 Troubleshooting FAQ

Can WPS Office fix this file format & compatibility issue directly? Only when the WPS steps match the formatting or file task. Account, activation, and cloud issues stay on the Microsoft side.

Should I reinstall Excel before trying these steps? Not first. Confirm account, license, and the exact error before reinstalling.

What should I send to Microsoft Support? The affected account email, device type, Office version, exact error text, and screenshots with personal data hidden.