Microsoft 365 Error Codes

How to Fix Microsoft Office Error 1001 When Opening or Signing In

Kushani Nimanthika Sep 28, 2026 870 views

Question details

The user is unable to open or sign into Microsoft Office desktop applications due to an Error 1001 prompt.

How to Fix Microsoft Office Error 1001 When Signing In

Product: Microsoft Office 365
Device & OS: Windows
Scenario: Launching or signing into Microsoft 365 desktop applications on a Windows computer.
Observed behavior: The application displays a 'Something went wrong [1001]' error message, blocking access to the Office software.

Before you start

Before proceeding with advanced troubleshooting, restart your computer and ensure that your Windows operating system is fully up to date, as pending updates or a simple reboot can sometimes resolve authentication anomalies.

Solution 1Recommended

Re-register Authentication Plugins via PowerShell

Use Windows PowerShell to repair the Web Account Manager and AAD Broker Plugin, which frequently resolves error 1001.

Error 1001 is heavily linked to a breakdown in communication with the Web Account Manager (WAM) plug-in. Running a specialized command under the affected user's account can re-register the Cloud Experience Host and AAD Broker Plugin to restore sign-in functionality.

Open Windows PowerShell

Press the Windows key, type 'PowerShell' into the search bar, and select 'Run as Administrator'. If instructed by your IT department, you may need to run this under the affected standard user account.

Execute the Re-registration Command

Type or paste the appropriate Microsoft-provided PowerShell command to re-register the AAD Broker Plugin and Cloud Experience Host, then press Enter.

Restart Your Computer

Once the PowerShell script completes successfully, close the window and restart your Windows device. Attempt to launch and sign into Microsoft Office again.

Re-register Authentication Plugins via PowerShell

System Administrator Rights: Some PowerShell commands may require administrative privileges. If you are on a work computer, you might need to contact your IT support team to perform this step.

Solution 2

Test with a New Windows User Profile

If the issue stems from deep profile corruption, creating a new local Windows account can help isolate and bypass the problem.

Free Microsoft Office alternative

Switch to WPS Office to Avoid Complex Sign-in Errors

Tired of dealing with frustrating authentication issues like Microsoft Office Error 1001? WPS Office is a highly compatible, free, and lightweight alternative that allows you to create, edit, and save documents instantly without restrictive sign-in roadblocks.

1. Download the Installer: Visit the official WPS Office website and click the free download button to get the latest lightweight installer.
2. Install WPS Office: Run the downloaded setup file and follow the quick on-screen instructions to install the suite on your Windows PC.
3. Open Your Files Instantly: Double-click your existing Word, Excel, or PowerPoint files to open them seamlessly in WPS Office without encountering Error 1001.

No complex subscription checks or sign-in roadblocks preventing accessFully compatible with Microsoft Office formats (.docx, .xlsx, .pptx)Lightweight installation with incredibly fast startup timesFamiliar user interface makes migration seamless and intuitive

microsoft office alternative - wps office

Frequently Asked Questions

What exactly causes Microsoft Office Error 1001?

Error 1001 is typically caused by issues with the Windows Web Account Manager (WAM), interference from overzealous security and antivirus software, or a damaged Windows user profile that fails to process Microsoft 365 authentication tokens.

Does Error 1001 mean my Microsoft account has been deleted?

No. Error 1001 is a local device and application issue relating to how your Windows computer communicates with Microsoft's servers. Your account, subscription, and cloud files remain safe and active.

Can my antivirus software trigger Error 1001 during sign-in?

Yes. Certain third-party antivirus or endpoint security programs can block the AAD Broker Plugin from connecting to the internet. Temporarily disabling your antivirus while signing in can help determine if this is the cause.

Microsoft Office Error Codes