Lock the Doors: AI Security Basics for a Small Office · Lesson 3 of 7

What your AI apps can see on each computer

20 minutes. Five minutes a machine. Switch off what doesn't need to be on.

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When you install an AI app on a computer, it often asks for permission to do more: read your files, see your screen, control other apps. Someone clicks "Allow" so the thing will work, and that permission stays on long after anyone remembers granting it.

That matters more now for two reasons. First, AI apps are getting better at acting on their own, so an app with broad permission can do more with it. Second, an app that can read everything is a bigger prize when it has a flaw. Apple said in early October 2026 that it will add more controls to the Mac's Full Disk Access setting because the risk grows as AI agents become more capable and independent. Microsoft is giving Copilot on Windows permission to work with your local files. Both companies are moving. You don't have to wait for them.

The rule for this lesson: each app gets the access its one job needs, and nothing more.

Everything lives in one place: Apple menu, then System Settings, then Privacy & Security. You'll see a list of categories. Five of them matter most for AI apps. Apple's own descriptions are in quotes.

| Category | What it allows | What to do | |---|---|---| | Full Disk Access | "Allow apps to access all files on your computer, including data from other apps," such as Mail, Messages and Safari | The big one. An AI app should almost never be here. Switch off anything you don't recognize or that doesn't truly need to read the whole computer. | | Files & Folders | "Allow apps to access files and folders in different locations on this Mac," such as Desktop, Documents and Downloads | Narrower than Full Disk Access. Fine for an app that needs, say, Documents. Switch off folders it doesn't need. | | Accessibility | "Allow apps to run scripts and system commands to control your Mac" | This is how an app clicks and types for you. Only keep it on for an app you deliberately set up to do that. | | Screen & System Audio Recording | "Allow apps to record your screen and audio, or just your audio" | Meeting and screen-reading AI tools ask for this. Keep only the ones you use. | | Automation | "Allow apps to access and control other apps on your Mac" | An AI app controlling Mail or Messages is a send-on-your-behalf risk. Switch off unless you set it up on purpose. |

How to check each one:

• Select the category. You'll see a list of apps with a switch next to each.
• For each app, ask: do I recognize it, and does its job need this?
• If not, turn the switch off. If an app stops working later, it will ask again, and you can decide then with your eyes open.

Turning a switch off doesn't delete the app or its data. It just takes the key back.

What's coming: Apple hasn't said when the new Full Disk Access controls will arrive or what they'll look like. When your Mac updates and this screen changes, do this check again.

Windows has two places to look.

1. Windows' own file permissions

Go to Start, then Settings, then Privacy & security, then File system. You'll see a main switch, Let apps access your file system, and a list of apps with their own switches. Turn off any app that doesn't need your files.

There's a catch, and Microsoft says it plainly: programs downloaded from the internet or installed from media don't always appear in that list. Many desktop AI apps are installed exactly that way. For those, the access is controlled inside the program's own settings. So do step 2.

2. Inside each AI app

Open each AI app installed on the computer and look in its settings for anything about files, folders, screen, or permissions.

• Copilot on Windows: Microsoft's help page says you can adjust what Copilot can reach under Account, then Settings, where File Search and File Read have their own switches. Microsoft redesigned the Copilot app in October 2026, with new sections that can reach local files and take actions in Windows, so if you don't see those words exactly, look for a "Permissions" area in Copilot's settings.
• Other AI desktop apps (Claude, ChatGPT and others): look for settings about local files, folders, screen sharing or "computer use." If a feature lets the app act on your computer and nobody uses it, turn it off.

Not sure? On Windows, ask your IT partner one question: "Which AI apps on our computers can read files broadly or take actions, and can you show me where that's controlled?" If they manage your computers with their own tools, they may be able to check every machine at once, which is faster than walking desk to desk.

Add this line to your staff AI rules (the course Write Your Team's AI Rules in an Afternoon walks you through the rest):

> No AI app gets access to company files, the screen, or control of the computer until the owner approves it.

It's much easier to set that rule before the next "Allow" button shows up than after.

Open the Computer Permission Check template.

• Start with your own computer. Fill in one row: computer name, who uses it, Mac or Windows.
• Go through each category above. Write down every AI app you find with broad access, and what you switched off.
• Do the same for the next computer, and the next, until every computer in the office has a row. If there are more than five or six, do two a day, or hand the template to your IT partner.

Check it worked

• Every computer in the office has a row with a date.
• No AI app has Full Disk Access unless you can say, in one sentence, why it needs it.
• On Windows, you've looked inside each AI app's own settings, not just the Windows list.
• Anything you couldn't figure out is written down as a question for your IT partner.

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Next: the AI tools that reach into your accounts, not just your computer.

→ Lesson 4: Connectors, agents and the accounts behind them

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