How to Set Up AI on Your Computer Properly

If you've only ever used ChatGPT on your phone or in a browser tab, you're using a fraction of what AI can do. This guide gets you set up with a desktop "super app" so AI can do jobs for you, not just answer questions.

Three routes: Claude, ChatGPT with Codex, or a budget setup. Pick one. You can always try the others later.

Chat apps vs super apps

A chat app is a conversation. You ask, it answers, you copy and paste the answer somewhere and do the work yourself.

A super app wraps the same AI model in a harness: a set of tools it can use on your computer. It can read and create files, run tasks in the background, and use your web browser to click, type and fill in forms.

Same brain, but now it has hands. That's the whole difference, and it's why everything I share in the newsletter starts here.

Which one should you pick?

Claude and ChatGPT are close enough now that you won't go wrong with either. I lean Claude. Anthropic's focus on safety sits better with me, I find the app easier, and its remote control from my phone has been more reliable for me. Codex has a brilliant voice mode, where you just talk to it like Jarvis while it works in the background.

I'm on Claude's top plan (Max, about £180 a month) because I use it all day for work. You don't need that. The £18 plan is plenty to start.

Route 1: Claude

1. Go to claude.com/download and install the app for your computer (Mac, or Windows 10 and above).
2. Sign in, then upgrade to Pro. Chat works on the free plan, but Claude Code needs a paid plan.
3. Open the Code tab. This is Claude Code: the part that works on your files.
4. Choose a folder for it to work in (see "The one rule" below).
5. For the browser bit (filling in forms, listing things for sale), install the Claude in Chrome extension from the Chrome Web Store and sign in with the same account. It's included on every paid plan.

You'll also notice Claude no longer makes you choose between chat and bigger tasks (what used to be called Cowork). Since mid-September they're one experience: ask a quick question or hand over a bigger job from the same place.

Route 2: ChatGPT with Codex

1. Download the ChatGPT desktop app for Mac or Windows.
2. Sign in, then upgrade to Plus if you're not on it already.
3. Top left, switch from ChatGPT to Codex. Codex is the part that works on your files and computer.
4. Choose a folder for it to work in.

Inside the ChatGPT side you'll also see a Chat / Work toggle. Chat is the normal conversation. Work is for bigger jobs like building documents, slides and spreadsheets. For everything I'll be teaching, Codex is where you want to be.

Route 3: On a budget with OpenCode

OpenCode is a free app that does the same job as Claude Code or Codex. The difference is that it doesn't come with a model. You bring your own, and pay only for what you use.

That's where open-source models come in. The Chinese labs (DeepSeek, Zhipu's GLM, Moonshot's Kimi) release models that cost a tiny fraction of Claude or ChatGPT. I've used DeepSeek and GLM in OpenCode, and Kimi in other tools.

My honest take: about six months ago, GLM in OpenCode felt roughly 70% as good as Claude. They've improved a lot since, and I've learned why they were falling short. It mostly comes down to how you set them up, which I'll cover in a series on getting open models to perform like the big ones.

One thing to understand first: OpenCode isn't a chat app like ChatGPT. It's the harness. Until you connect a model to it, it can't do anything.

Setting it up with DeepSeek

1. Download OpenCode from opencode.ai/download (Mac, Windows or Linux; the desktop app is in beta).
2. Go to the DeepSeek platform (platform.deepseek.com), create an account and add a few pounds of credit.
3. Create an API key and copy it. Treat it like a password: don't share it or paste it anywhere public.
4. In OpenCode, connect a provider (type /connect), search for DeepSeek and paste your key.
5. Pick a model (type /models). Start with DeepSeek's main model.
6. Choose your folder and you're away.

GLM works the same way, with a key from Z.ai instead of DeepSeek.

If this feels like a lot, start with Route 1 or 2 and come back to this once you're comfortable. Nothing wrong with that.

The one rule: give it one folder

This is the bit that confused me most when I started.

These apps work inside a folder you choose. Whatever's in that folder, they can read and change. So while you're learning:

• make a new folder on your desktop called AI
• always start your sessions in that folder
• don't point it at your whole computer and let it do whatever it wants

The apps will also ask your permission before reading files, changing things or using your browser. Read what they're asking before you say yes. That's a feature, not an annoyance.

Your first task

Drop a couple of photos of something you'd sell into your AI folder. Then paste this:

Look at the photos in this folder. Write me a Facebook Marketplace listing: a title, a fair price based on what similar items go for, and a short description that would make someone message me.

In a minute or so you'll have a listing ready to go. That's AI looking at files on your computer and doing a job, not just answering a question.

In next week's newsletter I'll take it further with a video: getting AI to open Marketplace in the browser and fill the listing in for me, so all I do is check it and hit publish.

No laptop?

Stick with the ChatGPT or Claude app on your phone for now. You'll still get plenty from the newsletter, and when you do get on a computer, this guide will be here.

What's next

This is the foundation for everything I share in The Growth Toolkit newsletter: the tips, the setups and the way I work with AI day to day. If you want to see where this goes, here's the AI personal trainer I built and the AI tools I rate for running a business.

The models get better every few months, and the people already set up are the ones who feel that first.

Stuck? If you're on the newsletter, reply to any of my emails and tell me where. I read every one.

Mike McDonnell. I write The Growth Toolkit, a free Sunday email on freeing up time with better tools, AI and setups.