Microsoft Copilot Overview: The AI Assistant for Windows, Office and Teams

Hardly any software update in recent years has changed everyday office life as much as Microsoft Copilot. Anyone who starts a Windows computer today, opens a Word document, or gets invited to a meeting in Teams almost automatically encounters a small colorful icon that summarizes text, creates spreadsheets, or drafts presentations. For case workers, administrative staff and anyone who works daily with Office programs, Copilot is thus often their first serious contact with artificial intelligence at all – a building block of our overview of AI models compared.

From betting on OpenAI to its own AI operating system

• Microsoft Copilot website
• Open Copilot directly

By “AI operating system” we mean that Copilot today is no longer just a single app, but a layer that runs in the background across Windows, Office and Teams alike – similar to how an operating system itself is available across all programs.

Microsoft first invested in the then-unknown research lab OpenAI back in 2019. After the success of ChatGPT in late 2022, the company massively expanded this partnership and brought the underlying language models into almost every one of its own products: into the Bing search engine, into Windows, into Microsoft 365, and into GitHub’s developer tools. What started as the codename “Bing Chat” became the unified Copilot brand in 2023, which has since brought together all of Microsoft’s AI features under one name.

The partnership with OpenAI in transition

This partnership is no longer a one-way street. Microsoft has invested billions in OpenAI and, in return, received exclusive access to its models via its own cloud platform, Azure. At the same time, OpenAI has meanwhile also become an independent competitor with its own consumer products, which is why the relationship between the two companies is regularly described as tense in trade press. In practice, this means: Microsoft continues to rely on OpenAI as its most important model supplier, but has deliberately broadened its base. Since 2025, Microsoft 365 Copilot has additionally offered models from Anthropic, so that companies can choose between different AI models depending on the task, without switching providers.

Copilot is not a single AI model, but an interface behind which several models from different manufacturers work – Microsoft itself calls this its “Model Choice” strategy.

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Copilot in everyday use: where it shows up

For beginners, it’s often confusing that “Copilot” is not a single product, but a family name for several, sometimes very different tools. The following overview shows the most important places it appears in normal everyday office work.

Copilot in Windows

Since Windows 11, Copilot has been integrated directly into the taskbar. A click opens a chat window that answers questions, explains system settings, or helps with drafting text. This basic version is free and, for many users, their very first point of contact with generative AI at all.

Copilot in Word, Excel and Outlook

In Word, Copilot drafts text templates, summarizes long documents, or adjusts the tone. In Excel, it can explain formulas on request, structure spreadsheets, or build initial analyses from raw data. In Outlook, it summarizes long email threads and suggests replies. This deep integration into the individual Office programs remains, to this day, the core advantage of Microsoft’s approach compared to pure chat tools: you don’t need to copy the text and paste it into a separate window, but keep working directly in the familiar document.

Copilot in Teams

In video conferences, Copilot can take notes live, generate a summary with a task list at the end, and flag open questions that were not answered during the meeting. For teams with many recurring meetings, this has meanwhile become one of the most frequently used features of all.

Copilot Pro and Microsoft 365 Premium

For private users and small self-employed people, there was for a long time a standalone subscription called Copilot Pro. Microsoft restructured this offering over the course of 2025: new customers have no longer been able to sign up for Copilot Pro on its own since October 2025; the features were instead moved into the new Microsoft 365 Premium package. Anyone who still has an existing Copilot Pro subscription can continue to use it, but a renewal is now only possible on a transitional basis.

Pricing and subscription tiers at a glance

Microsoft’s pricing structure is tiered and depends on whether you’re a private individual, a small business, or a larger organization. The following table shows the most important tiers as they stood in summer 2026. Since Microsoft regularly adjusts prices and they vary by region, the figures should be understood as guidance.

Important for businesses: the Business and Enterprise tiers are purely add-on licenses. Copilot cannot be purchased in isolation; it requires an existing Microsoft 365 or Office 365 license on top of which it is layered.

Data protection and GDPR: what actually applies

Business version and private version are not the same

When assessing data protection, a strict distinction must be made between the free consumer version and the business variants. For Microsoft 365 Copilot in business environments, the contractual privacy commitments that Microsoft gives to business customers anyway apply: inputs and company data are not used to train the general AI models, and the data stays within the contractually guaranteed boundaries of the respective Microsoft 365 tenant. For the free consumer version in Windows or in the private Bing Chat, on the other hand, different, considerably weaker commitments apply, as is usual for private consumer products.

The EU Data Boundary

For customers in the European Union, Microsoft operates what is known as the EU Data Boundary. It ensures that data belonging to European business customers is generally processed and stored in European data centers, for example in Frankfurt, Dublin or Amsterdam. Microsoft is continuing to expand this offering in 2026 and is gradually bringing local processing to further countries as well.

An important exception

Anyone relying on the EU Data Boundary should be aware of one point: since Microsoft additionally integrated Claude models from Anthropic into Copilot alongside the OpenAI models, requests that run via these models currently do not yet carry a full guarantee of the EU Data Boundary, since Anthropic hosts predominantly on servers in the USA. For everyday text work in Word or Excel, this is rarely relevant, but for sensitive data sets, it’s worth checking the current admin settings of the respective tenant.

Anyone working at a German company with personal or particularly sensitive data should check exactly which model is active for which application in the Copilot admin settings, rather than relying on a blanket assumption of “GDPR-compliant data protection.”

Strengths and weaknesses

Who is Microsoft Copilot suited for

The benefit is greatest for anyone who works with Office programs daily.

• Case workers in administrative offices
• Real estate agents and property managers with correspondence
• Accounting and sales
• Small offices doing spreadsheet work

Anyone wanting a standalone chat app without Microsoft ties will find cheaper alternatives elsewhere. For German hosting of property data or leases, Lukinski AI without a US cloud connection is worthwhile.

Practical example: what Copilot costs for a small office

A real estate office with eight employees uses Copilot as an add-on license.

• Around 22 euros per user/month
• About 176 euros in team costs/month
• A good 2,100 euros extra per year

Whether this is worthwhile depends on how much time employees spend on text work and email correspondence – exactly where Copilot comes in.

Frequently asked questions about Microsoft Copilot

Can Microsoft Copilot be used for free?

The basic version in Windows and in the browser is free. For full integration into Word, Excel, Outlook and Teams, as well as priority access to more powerful models, a paid tier is required.

Which AI model is behind Microsoft Copilot?

Predominantly models from OpenAI, currently mainly from the GPT-5 series (GPT stands for “Generative Pre-trained Transformer,” the technical model family behind ChatGPT), supplemented since 2025 by models from Anthropic. Which model is used in detail is explained on the linked in-depth page on the Copilot models.

Is Copilot Pro still available?

No, new customers have not been able to sign up for Copilot Pro since October 2025; the features have been moved into Microsoft 365 Premium. Existing subscriptions continue on a transitional basis.

Is Microsoft Copilot GDPR-compliant?

For business customers, contractual privacy commitments apply, including the EU Data Boundary, though with an exception for certain add-on models. The free consumer version is subject to weaker commitments than the business version.

Is Copilot worthwhile for small offices too?

Yes, especially if a lot of work involves Word, Excel or email correspondence. For very specific business applications with high data protection requirements, complementary, specialized solutions can make sense.

Anyone wanting to understand in more detail which Copilot variant uses which model, and how the individual tiers differ, will find a detailed comparison on the in-depth page Microsoft Copilot models in detail.