How to Use Copilot Cowork for Long Running Office Tasks

You have a large document to summarize or a complex spreadsheet to analyze, but you cannot sit and wait for the process to finish. Running a long task in Microsoft 365 often means keeping your computer on and your session active, which blocks you from doing other work. Copilot Cowork is a feature that runs these operations in the background so you can close the file or even the application and come back later. This article explains what Cowork is, how to set it up, and how to avoid common mistakes when using it.

What Is Copilot Cowork and How Does It Handle Long Tasks

Copilot Cowork is a feature that lets you offload long-running Office tasks to a server-side process. When you start a task like summarizing a 500-page Word document or analyzing a dataset in Excel, Copilot Cowork moves that work to Microsoft 365 cloud infrastructure. You can close your laptop, switch to another app, or even log off. The task continues on the server. When the work finishes, you receive a notification and can view the output in the same app or on a different device.

The feature relies on Microsoft Graph and your Microsoft 365 tenant resources. It is available in Copilot for Microsoft 365 with an enterprise or business license. Cowork does not require any additional software. It works inside Word, Excel, PowerPoint, and OneNote. The background process uses the same permissions and data access policies as the standard Copilot experience. No extra setup is required beyond having the right license and an internet connection.

Prerequisites for Using Cowork

Before you can use Copilot Cowork, you need a Copilot for Microsoft 365 license assigned to your account. The feature is also available in Microsoft 365 Copilot Chat with a Microsoft 365 Copilot license. Your organization must have the background task processing enabled in the Microsoft 365 admin center. Check with your IT administrator if you do not see the Cowork option. The file you want to process must be stored in OneDrive for Business or SharePoint Online. Local files cannot be used with Cowork because the server needs access to the file during processing.

Steps to Start a Copilot Cowork Task in Word and Excel

The process for starting a Cowork task is the same across Word, Excel, and PowerPoint. The steps below use Word as an example.

1. Open the document in Word for the web or desktop
   Make sure the file is saved to OneDrive for Business or SharePoint Online. If you are using the Word desktop app, sign in with your work or school account. The file must be synced to the cloud for Cowork to access it.
2. Open the Copilot pane
   Click the Copilot icon on the Home tab or press Alt+I to open the Copilot pane. If you do not see the icon, go to View > Show Copilot to enable it.
3. Select the Cowork tab
   In the Copilot pane, click the Cowork tab. It is the second tab next to Chat. If you do not see the Cowork tab, your license may not include background tasks or your admin has disabled the feature.
4. Choose a task type
   Click the dropdown menu under Task type and select the operation you want to run. Options include Summarize document, Extract key points, Translate to another language, and Analyze data. Excel offers Analyze table and Generate charts.
5. Configure task options
   Depending on the task, you may need to specify parameters. For translation, select the target language. For data analysis, choose the range or table. For summarization, set the output length to Brief, Normal, or Detailed.
6. Click Start background task
   Copilot Cowork begins processing. A progress indicator appears in the Cowork tab showing the status. You can close the document now. The task continues on the server.

Checking Task Progress and Viewing Results

You do not need to keep the document open to track progress. Open any Microsoft 365 app and go to Home > Copilot Cowork status. A panel shows all your active and completed tasks. Click a completed task to open the output in the original app. For example, a completed summarization in Word opens a new document with the summary. You can also access results from the Copilot pane in the original file. Reopen the file and click the Cowork tab. Completed tasks appear under History.

If Copilot Cowork Does Not Start or Fails Midway

Even when you follow all steps correctly, Cowork may fail to start or stop processing before completion. Below are the most common problems and what causes them.

Cowork Tab Is Missing from the Copilot Pane

The Cowork tab appears only if your Microsoft 365 tenant has background task processing enabled. If the tab is missing, contact your IT administrator. They need to enable the setting in the Microsoft 365 admin center under Copilot > Background tasks. Also verify that you have a Copilot for Microsoft 365 license. The feature is not available in consumer Copilot subscriptions.

Task Shows Error: File Not Accessible

Cowork requires the file to be stored in OneDrive for Business or SharePoint Online. If you are working on a local file, save it to the cloud first. If the file is already in the cloud but still shows an error, check your sharing permissions. The file must not be shared with external users in a way that blocks internal processing. Re-save the file with a new name and try again.

Task Stops at 50% or 75% Completion

This usually happens when the file exceeds the size limit for Cowork processing. Microsoft currently limits background tasks to files under 500 MB. For files larger than that, split the document into smaller sections and run Cowork on each part. Another cause is a network interruption that disconnects your session from the server. Wait a few minutes and check the status again. The server retries automatically up to three times before marking the task as failed.

Copilot Cowork vs Standard Copilot Inline Processing

Item	Copilot Cowork	Standard Copilot Inline
Processing location	Server-side in Microsoft 365 cloud	Local session or client-side
Requires file to stay open	No, you can close the app	Yes, the app must remain open
Maximum file size	500 MB	No hard limit, but performance degrades over 100 MB
Output delivery	Notification and stored in cloud	Inline in the Copilot pane
Best for	Large documents, long analysis, translation	Quick answers, short summaries, small edits

Use Cowork when you need to process a file that takes more than a few minutes. Use standard Copilot for instant responses on small tasks. Both features use the same AI model but differ in how they handle the workload.

You can now start background tasks in Word, Excel, and PowerPoint without keeping your computer on. Use the Cowork tab in the Copilot pane to offload large summarization, translation, or data analysis jobs. Check your task status from any device using the Home > Copilot Cowork status menu. For best results, keep files under 500 MB and save them to OneDrive for Business or SharePoint Online before starting a Cowork task. If you frequently work with large documents, set up email notifications in Copilot Cowork settings so you never miss a completed task.