AI Agents and Agentic Coding in 2026: What Changed, and What It Means for Windows and Office Users

Short answer: In 2026, AI agents moved from demos into the software most people already use. An AI agent is a program that takes a goal, plans the steps itself and carries them out across apps and files; “agentic coding” is the same idea applied to software development. This year the numbers caught up with the hype: 90 per cent of professional developers use AI coding agents at least weekly (JetBrains, August 2026), Copilot’s Agent Mode became the default in Word, Excel and PowerPoint for subscribers, and on 25 September 2026 Microsoft unveiled a new Copilot app with always-on agents. For an ordinary Windows or Office user nothing changes unless you opt in: agent features need a subscription, a Copilot+ PC or both, and a one-off licence such as Office 2024 works exactly as before. For a small business the practical question is which repetitive task to hand over first – and who checks the result.

What is an AI agent, and what is “agentic coding”?

An AI agent is software that receives an outcome (“reconcile these invoices”, “fix the failing tests”), breaks it into steps, uses tools such as a browser, a spreadsheet or a terminal, checks its own work and reports back. A chatbot gives one reply per message; an agent runs a loop of planning, acting and checking until the job is done or it needs a decision from you.

Agentic coding is that loop applied to programming. A coding agent such as Claude Code, Codex or GitHub Copilot’s coding agent reads a whole project, writes and runs code, fixes errors and hands a finished change to a human for review. Anthropic’s 2026 Agentic Coding Trends Report puts the human side plainly: developers use AI in roughly 60 per cent of their work but say they can fully delegate only 0 to 20 per cent of tasks.

What changed in 2026: a short timeline

OpenAI describes GPT-6 Astra as able to “take care of tedious tasks like filling out online forms, updating customer records in a CRM”. Anthropic says one early tester of Claude Opus 5.5 completed “a 680,000-line code migration in less than a day”. Those are vendor claims, not independent tests, but they show where the products are aimed: hours-long jobs, not single answers. For a comparison of the assistants themselves, see ChatGPT vs Claude vs Gemini vs Copilot in 2026.

How many people actually use agents?

Developers, overwhelmingly; everyone else, selectively. JetBrains’ Developer Ecosystem Survey 2026 (May–July 2026, more than 15,000 professional developers) found Claude Code in use by 39 per cent of respondents, GitHub Copilot by 21 per cent, Codex by 16 per cent and Cursor by 12 per cent. Stack Overflow’s pulse survey of 1,100 developers and professionals in late April 2026 found 37 per cent using agents daily, up from 14 per cent in its 2025 survey, while 69 per cent still work with a single agent rather than a team of them.

Outside software, adoption is slower and shallower. The Office for National Statistics reported on 20 July 2026 that about 35 per cent of UK businesses with ten or more employees used at least one AI technology in June 2026, up from around 12 per cent in September 2023. Among the smallest firms (0 to 9 employees) the figure was 28 per cent; among large firms (250 or more) it was 49 per cent – and only 10 per cent of AI-using businesses said they use AI extensively.

What it means for ordinary Windows and Office users

Agents in Windows 11

Windows 11 now has two kinds of agent feature. The first is the agent in Settings, which uses a small on-device model (Microsoft calls it “Settings Mu”) to find and change settings from a plain-English request. According to Microsoft’s documentation it requires a Copilot+ PC running Windows 11 version 24H2 with the July 2025 update or later. The second is the set of experimental agentic features (Copilot Actions and the agent workspace). These are off by default, can only be switched on by an administrator, and Microsoft’s own support note warns that “malicious content embedded in UI elements or documents can override agent instructions, leading to unintended actions like data exfiltration or malware installation”. If you do not turn them on, your PC behaves as it always has. The edition matters less than the hardware: both Home and Pro can receive these features, as explained in our Windows 11 Pro vs Home guide.

Agents in Word, Excel and PowerPoint

Copilot Agent Mode lets you describe a result (“build a quarterly summary with a chart from this sheet”) and watch Copilot carry out the edits itself. It requires a Microsoft 365 Copilot add-on, a Microsoft 365 Premium plan, or a Personal or Family plan with AI credits. The new Copilot app announced on 25 September 2026 goes further: a Home section with a “Cowork” agent, a Code section for building small apps by describing them, an Autopilot section for always-on agents, and Word, Excel and PowerPoint inside Copilot, with a choice of OpenAI or Anthropic models. Microsoft said agent work would be billed on usage on top of the per-user licence.

None of this applies to perpetual licences. Microsoft’s documentation states that Office LTSC 2024 “doesn’t include the latest cloud-backed features” and that users “don’t have access to real-time collaboration, AI-driven automation”. If you want Word, Excel, PowerPoint and Outlook that do not change under you and never bill per agent, a one-time licence such as Office 2024 Professional Plus is the predictable option, and any AI assistant can still be used alongside it in a browser. We compare the two models in Office 2024 vs Microsoft 365.

What it means for small businesses

Agents are most useful where a task is repetitive, well defined and easy to check. Developers who use agents daily still review the output, and the ONS data shows most UK firms are experimenting rather than running the business on AI. A sensible approach for a small firm:

1. Pick one task with a clear “done”. Sorting an inbox, drafting first replies, turning a sales export into a monthly report, or reconciling two spreadsheets. Our article on AI software automation for business lists more examples.
2. Decide who signs off. Stack Overflow found 60 per cent of professionals block agents from making unapproved system changes. Copy that rule: agents draft, people approve.
3. Keep the agent’s reach small. One folder, one mailbox or one sheet – not the whole file server. Microsoft’s warning about prompt injection applies to any agent that reads documents from outside your business.
4. Budget per task, not per seat. Microsoft’s new Copilot bills agent work on usage; OpenAI and Anthropic price by tokens. Start with a capped monthly amount and measure the hours saved.
5. Keep the base software current. An agent is only as safe as the operating system it runs on; a supported Windows 11 release with a properly activated licence is the minimum.

Frequently asked questions

What is the difference between an AI assistant and an AI agent?

An assistant answers your question and waits. An agent is given a goal, plans the steps, uses tools such as files, browsers and apps, and comes back when the job is finished or it needs a decision.

Do I need a Copilot+ PC to use AI agents on Windows 11?

Only for on-device features such as the agent in Settings, which Microsoft lists as requiring a Copilot+ PC on Windows 11 version 24H2 or later. Cloud-based agents from OpenAI, Anthropic, Google and Microsoft run in a browser on any current Windows 11 PC.

Does Office 2024 include Copilot or Agent Mode?

No. Microsoft states that Office LTSC 2024 does not include cloud-backed features or AI-driven automation. Agent Mode in Word, Excel and PowerPoint requires a Microsoft 365 subscription with Copilot. You can still use AI tools next to Office 2024 through their own apps or the browser.

Are AI agents safe to use in a small business?

They can be, with limits. Microsoft warns that agents can be hijacked by malicious text hidden in documents or web pages (cross-prompt injection). Keep agents off by default, give them access to as little as possible, and have a person approve anything that sends money, emails customers or changes systems.

How many developers use agentic coding tools?

JetBrains’ 2026 survey of more than 15,000 professional developers found 90 per cent using AI coding agents at least weekly and 68 per cent daily, with Claude Code (39 per cent) the most widely used, followed by GitHub Copilot (21 per cent) and Codex (16 per cent).

Sources

• Anthropic, “2026 Agentic Coding Trends Report” (PDF), accessed 6 October 2026 – resources.anthropic.com
• JetBrains Research, “AI Coding Agents: Adoption Trends”, 19 August 2026 – blog.jetbrains.com
• Stack Overflow, “Agents on a leash: Agentic AI remains mostly single-agent and monitored at work”, 27 May 2026 – stackoverflow.blog
• Office for National Statistics, “Artificial intelligence in UK businesses: 2023 to 2026”, 20 July 2026 – ons.gov.uk
• GeekWire, “Microsoft unveils all-in-one Copilot app, taking on Anthropic and OpenAI…”, 25 September 2026 – geekwire.com
• Office Watch, “Copilot Agent Mode Word Excel PowerPoint Explained”, 27 April 2026 – office-watch.com
• Microsoft Learn, “Configure the agent in Windows Settings”, updated 27 February 2026 – learn.microsoft.com
• Tom’s Hardware, “Microsoft’s new agentic AI features introduce new security risks…”, 19 November 2025 – tomshardware.com
• OpenAI, “GPT-6 Astra: A new generation of intelligence”, September 2026, accessed 6 October 2026 – openai.com
• Anthropic, “Introducing Claude Opus 5.5”, 22 September 2026 – anthropic.com
• Microsoft Learn, “Overview of Office LTSC 2024”, updated 22 January 2026 – learn.microsoft.com