This week's editionAI · business · made in MouginsThe letter goes out Friday at 9 am
Guide · 100

AI working
on your
computer.

You know how to ask ChatGPT or Claude a question. But you're still copying the answer yourself into a spreadsheet, a document, a folder. Since 2026, their desktop apps can do that work for you, right on your files. You open a folder for them, write what you want, and get back a finished document. Here's how to get started, with five starter tasks and the settings that prevent nasty surprises.

10 min read Level Beginner Tools Claude app, ChatGPT Work
In 30 seconds

What you'll walk away with

Before you start

For months, my AI use looked like this: I'd ask a question, copy the answer, paste it into a spreadsheet, reformat it, file it. AI did the interesting part, and I did the painful part.

What changed in 2026 is that Claude and ChatGPT's desktop apps can now do the painful part too. You hand them a folder and instructions in English, and they read your files, create new ones, and give you a result you only have to proofread.

My take in 5 seconds

It's the biggest time saver I've seen for a non-developer since ChatGPT. But it's also the first time AI touches your real files, so we start small, in a test folder.

What changes compared to chat

In chat, AI gives you an answer. Then you have to apply it yourself. With the desktop app, you give it a goal, it breaks the work into steps and does it. That's what we call agent mode.

The two big tools each have their own way:

In both cases, you don't write a line of code and you don't open any technical screen.

Install the app and open it

You need a paid subscription. Claude Pro costs $20 per month before tax, ChatGPT Plus also around $20 per month, both with no commitment. The free versions are enough for chatting, not for this work mode.

  1. Download the app. Claude at claude.com/download, ChatGPT at chatgpt.com/download. Both exist for Mac and Windows.
  2. Install it like any application, then log in with your account.
  3. Create a test folder on your desktop, for example "ai-test", and put two or three unimportant files in it.
  4. Open this folder to the AI. In Claude, give it access to this folder. If you still see two buttons, "Chat" and "Cowork", choose Cowork. In ChatGPT, choose ChatGPT in the menu, then Work with the selector.

The screens change fast at both companies. If a button isn't exactly where I say it is, ask the AI directly: "how do I give you access to a folder on my computer?" It will guide you.

Five starter tasks to try

Copy each message exactly as is. Only replace what's in brackets.

Task 01 · Tidy a folder

Your Downloads folder, finally sorted

Open your Downloads folder to the AI, or a copy if you'd rather be safe.

Sort this folder by file type: documents, images, spreadsheets, others.
Put anything older than 6 months into an Archive subfolder.
Don't delete anything. Show me what you moved.

You get a tidy folder and the list of what moved.

Task 02 · Expense spreadsheet

From PDF invoices to a clean spreadsheet

Put your invoices for the month in the folder.

Read all the PDF invoices in this folder.
Create a spreadsheet with date, vendor, pre-tax amount, tax, and total amount.
Add a total row. If any information is missing, leave the cell empty and tell me.

You get a spreadsheet ready to open. Check two or three random rows before using it.

Task 03 · Compare quotes

Three quotes, a reasoned choice

From the quotes in this folder, make a comparison table: price, timelines, warranties, what's included and what isn't.
Tell me which one you'd choose for [your main criterion] and why, in 5 lines.

The table saves you from rereading three PDFs side by side. The decision stays yours.

Task 04 · A presentation

Your notes become 10 slides

From my notes in this folder, create a 10-slide presentation for [your audience].
One idea per slide, short titles, no more than 4 lines of text per slide.

You get a file you open in PowerPoint, Keynote, or Google Slides to adjust.

Task 05 · A web page

Your business page

In this folder, create a simple web page that presents my business: [your job and city].
Explain in simple words what you do.
When it's ready, show me the result.

It's the exercise from step 3 of the Learn path. You just had something built without a single line of code.

Security settings

These apps act for real on your files. Three things to know before handing them more than a test folder.

With Claude, the Auto or Manual setting

In the message area, a setting decides how much Claude works on its own. Auto, the default on Pro subscriptions, lets it move forward without asking you at each step, with automatic checks before acting. Manual makes it ask for your approval before each action. For your first tasks, switch to Manual: you'll see exactly what it does.

Claude only touches your files while the app is open, and it asks before permanently deleting a file.

With ChatGPT, permissions

In the desktop app, Work only uses your files and applications with your permission. The work can run on your computer, but the messages and task context may be stored in the cloud. Keep that in mind for sensitive documents.

The rule that applies to both

Everything the AI reads to do the task goes to the publisher to be processed, just like in chat. To go further on this topic, read what AIs do with your data.

What not to let it touch

My checklist before every task

(1) Only one folder open, and I have a copy. (2) My instruction says what it must not do, for example "don't delete anything". (3) I proofread the result before sending it to anyone.

What now?

Do task 05 right now, it's ten minutes. Then pick a repetitive task from your week and hand it over, in a test folder. If you want to go further and chain actions on your own, read how to automate your tasks without code.

Sources

These apps evolve every month. If a screen has changed, write to me, I update the guide.

Jérémy Sagnier
Thanks for reading this far 👋

Shall we keep going?

I test AI for real and share what works, with no jargon or hype. If this article helped you, the easiest way to miss nothing is my Friday letter. And if you have a question or a doubt: reply to me, I read everything.

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