# How to protect a folder or file with a password

> Windows and macOS don't put a password on a single folder, but they have encryption tools: 7-Zip creates a password-protected archive, Disk Utility on Mac an encrypted disk image, BitLocker protects a whole drive. With the limits of each.

Source: https://simplebuild.it/tutorial/proteggere-cartella-password
Author: SimpleBuild, Build simple. Deliver value.
Category: Backup and security
Procedure verified on: 2026-09-30

Windows and macOS don't have a button to put a password on a single folder. But there are official tools that do the same thing, and better: on **Windows** you create an **encrypted archive** with the free program **7-Zip**; on **Mac** you create an **encrypted disk image** with **Disk Utility**, which comes built in. To protect the whole computer there's **BitLocker** (Windows) or **FileVault** (Mac).

## Before you start

- **If you lose the password, you lose the files.** There's no "back door": that's exactly what makes encryption secure. Write the password down somewhere safe, for example in a password manager (see [where to find your saved passwords](https://simplebuild.it/tutorial/password-salvate)).
- **Make a copy first** of the files you want to protect, on an external drive. If something goes wrong halfway, you lose nothing. If you don't have a backup yet, start with [how to back up a Windows PC](https://simplebuild.it/tutorial/backup-pc-windows) or [backing up your Mac with Time Machine](https://simplebuild.it/tutorial/backup-mac-time-machine).
- **Be wary of unknown programs and websites** that promise to "lock folders" or to put a password on files online. Some only hide the folder without encrypting it; websites, to work, have to receive your documents unencrypted.
- **Encrypting** means turning the content into a code that can't be read by anyone without the right password or key.

## On Windows 11 and 10: an encrypted archive with 7-Zip

7-Zip is a free, open-source program. The **7z** format uses **AES-256** encryption, which is very strong. With 7-Zip you create a file that contains your folder and only opens with the password.

### Download it

1. Go to the official website [7-zip.org](https://www.7-zip.org/download.html).
2. Download the **64-bit Windows x64** version (the most common) and install it. The program is also available in Italian.

### Create the password-protected archive

1. In **File Explorer**, right-click the folder you want to protect. In Windows 11, if you don't see the **7-Zip** item, first choose **Show more options**.
2. Choose **7-Zip > Add to archive...**.
3. Under **Archive format**, choose **7z**.
4. In the **Encryption** section, type the password in **Enter password** and repeat it in **Reenter password**. 7-Zip asks you to use only unaccented letters, numbers and special characters.
5. Check that the **Encryption method** is **AES-256**.
6. Check **Encrypt file names**: that way, without the password, nobody can even see what the documents are called.

   ![Diagram of 7-Zip's Add to Archive window: 7z format, the password typed twice, AES-256 method and the Encrypt file names checkbox ticked.](https://simplebuild.it/assets/img/tutorial/proteggere-cartella-password-7zip-en.svg)

7. Select **OK**.

A file with the **.7z** extension is created, with the name and in the location shown under **Archive**. To test it, right-click the file and choose **7-Zip > Extract files...**: it must ask for the password. Only after checking that it opens and that everything is inside, **delete the original folder** and empty the Recycle Bin. If you leave the original, the protection is useless.

### If you need a .zip file

You can choose the **zip** format in step 3 if the recipient doesn't have 7-Zip. The 7-Zip help warns that for zip you can choose between **ZipCrypto**, which opens almost anywhere but is weaker, and **AES-256**, stronger but read only by some programs. To open the archive later, see [how to open a ZIP or RAR file](https://simplebuild.it/tutorial/aprire-file-zip-rar).

## On Mac: an encrypted disk image with Disk Utility

A **disk image** is a file that, once opened, behaves like a USB stick: it appears on the desktop and you drag your documents into it. If it's encrypted, it only opens with the password.

### From a folder you already have

1. Open **Disk Utility** (find it by typing "Disk Utility" in the search).
2. Choose **File > New Image > Image from Folder**.
3. Select the folder and click **Open**.
4. Choose the file name and where to save it.
5. Click the **Encryption** pop-up menu, choose an encryption option and enter the password twice.

   ![Diagram of Disk Utility's save window: under the file name, the Encryption pop-up menu, then Image Format and Save.](https://simplebuild.it/assets/img/tutorial/proteggere-cartella-password-utility-disco-en.svg)

6. Under **Image Format**, choose **Read-only Compressed** if you only want to keep the files, or **RAW Image** if you want to be able to edit them later.
7. Click **Save**, then **Done**.

### An empty "safe" to fill

1. In Disk Utility, choose **File > New Image > Blank Image**.
2. Type the file name, the disk **Name** and the **Size** (the most it will be able to hold).
3. Under **Format**, choose **APFS**.
4. In the **Encryption** menu, choose an option, enter the password twice and click **Choose**.
5. Click **Save**, then **Done**.
6. In the Finder, copy your documents into the disk image.

Apple says it plainly: **if you forget the password, you won't be able to open the disk image**. And as long as the image stays open on the desktop, anyone using your Mac can read what's inside: when you're done, **eject it**. To open it again, double-click the file.

If you want to protect the whole Mac disk, not just one folder, Apple says to turn on **FileVault** in **Privacy & Security** settings.

## Protect the whole drive on Windows: BitLocker

If your worry is that someone steals the laptop and reads the drive, the solution is to encrypt the entire drive. Windows has two tools:

- **Device encryption**: available on **Windows Home** too. It's in **Settings > Privacy & security > Device encryption** and you turn it on with a toggle, signed in to Windows with an administrator account. If you sign in with a Microsoft account, it's often already on. If the item isn't there, your PC doesn't support it or you're signed in with a standard account.
- **BitLocker Drive Encryption**: only **Windows Pro, Enterprise or Education**. From **Start**, type "BitLocker", open **Manage BitLocker** and choose **Turn on BitLocker** next to the drive. Here you can also encrypt USB drives (**BitLocker To Go**).

In both cases there's a 48-digit **recovery key**. Windows may ask for it after a hardware or software change. **Microsoft can't recover it if you lose it.** From **Manage BitLocker**, choose **Back up your recovery key** and save it to your Microsoft account, to a USB drive or on paper. Keep it **away from the computer**.

Note: BitLocker protects the drive from someone who takes it and connects it elsewhere. While you're signed in to Windows, your files are readable as usual: it doesn't ask for a password for each folder.

### What about encrypting single files (EFS)?

In Windows editions other than Home there's also a checkbox to encrypt a folder: right-click > **Properties** > **Advanced...** > **Encrypt contents to secure data**. **It's not in the Home edition.** It isn't a password on the folder: the key that opens the files is stored in the computer, and if it's lost the files stay unreadable. For home use, a 7-Zip archive is easier to understand and to take elsewhere.

## On iPhone and Android

On phones there's no official, universal way to put a password on a folder of files. The phone is already protected by its unlock code: choose a long one and turn on [two-step verification](https://simplebuild.it/tutorial/verifica-in-due-passaggi) for your accounts.

## If it still doesn't work

- **7-Zip says "Wrong password?"**: check the Caps Lock key and the keyboard language. If you used accented letters, that's exactly why 7-Zip advises against them.
- **The recipient can't open the zip**: you probably chose AES-256 and their program can't read it. Make it again with ZipCrypto, knowing it's weaker, or have them install 7-Zip.
- **You can't find Manage BitLocker**: you have Windows Home. Use Device encryption, if it's there, or 7-Zip.
- **Windows asks for the recovery key at startup**: look for it in your Microsoft account or wherever you saved it. Without the key, the drive won't unlock.
- If you need to protect work or client documents, it's worth setting up encryption and backups once and for all with a technician, checking where the keys end up: that's the part that most often gets lost.

## Frequently asked questions

### If I forget the password for the archive or disk image, can anyone recover it?

No. Encryption exists precisely to block access without the password: Apple warns that without the password the disk image won't open, and Microsoft states that it can't recover a lost BitLocker recovery key.

### Can I email a password-protected archive?

Yes. The recipient needs a program that reads that format and must know the password. Send them the password another way, for example by voice or by text message, not in the same email.

### Are websites that put a password on PDFs or files safe?

To work, they have to receive your document as it is, before it's protected. For personal documents, a tool that works on your own computer is better, like the ones in this guide.

### Does Windows encryption protect USB drives too?

Yes, with BitLocker To Go, which is part of BitLocker Drive Encryption: you need Windows Pro, Enterprise or Education.

## Sources

- [7-Zip, official website](https://www.7-zip.org/)
- [7-Zip, download page](https://www.7-zip.org/download.html)
- [The 7z format and AES-256 encryption (7-Zip)](https://www.7-zip.org/7z.html)
- [Create a disk image using Disk Utility on Mac (Apple)](https://support.apple.com/guide/disk-utility/dskutl11888/mac)
- [Device Encryption in Windows (Microsoft)](https://support.microsoft.com/en-us/windows/security/encryption/device-encryption-in-windows)
- [BitLocker Drive Encryption (Microsoft)](https://support.microsoft.com/en-us/windows/security/encryption/bitlocker-drive-encryption)
- [BitLocker overview (Microsoft)](https://support.microsoft.com/en-us/windows/security/encryption/bitlocker-overview)
- [Back up your BitLocker recovery key (Microsoft)](https://support.microsoft.com/en-us/windows/security/encryption/back-up-your-bitlocker-recovery-key)
- [How to encrypt a file or folder (Microsoft)](https://support.microsoft.com/en-us/windows/security/encryption/how-to-encrypt-a-file-or-folder)
- [Back up the recovery agent EFS private key (Microsoft Learn)](https://learn.microsoft.com/en-us/troubleshoot/windows-server/certificates-and-public-key-infrastructure-pki/back-up-recovery-agent-efs-private-key)
- [File Explorer in Windows (Microsoft)](https://support.microsoft.com/en-us/windows/experience/fileexplorer/file-explorer-in-windows)