Files · Windows 10 and 11
Lock a folder with a password
Windows has no setting that puts a password on one folder. Octoolo does: choose the folder, type a password twice, and the folder becomes one locked file, Photos.olock, that shows nothing of what is inside. The password opens it again, in the same place, as it was.
How to lock a folder in Windows 11 or 10
- 1
Choose the folder
In Files, press A folder… under Lock, or drop the folder on that box. In File Explorer you can also right-click it and choose Octoolo, then Lock with a password… (on Windows 11, under Show more options).
- 2
Choose a password
Type it under Choose a password; the meter shows how hard it is to guess, from Very easy to guess to Very strong. Type it again under Type it again.
- 3
Add a hint, if you like
A hint, if you like is shown when you unlock, to anyone who has the locked file, so make it a reminder that only you understand, never the password itself.
- 4
Lock it
Press Lock this folder. The folder
PhotosbecomesPhotos.olockin the same place. To open it again, double-click it: see unlock a folder.
What Windows offers, and what it does not
Windows has no setting that asks for a password before a folder opens. What it does have:
- Encrypting File System (EFS), in the Pro, Enterprise and Education editions, encrypts a folder for your Windows account. It asks for no password of its own: whoever is signed in as you opens it as usual. Windows Home does not have it.
- BitLocker, on the same editions, encrypts a whole drive, not one folder.
- Hiding a folder only keeps it out of sight. Anyone who turns on hidden items sees it, and it opens as usual.
- A ZIP with a password works on any edition, but File Explorer's own ZIP cannot add a password, and a ZIP shows its file names to anyone: see password-protect a ZIP.
Octoolo's lock works the same on Home and Pro, and its password is one you choose for that folder, not your Windows sign-in.
What a locked folder looks like
The whole folder, with everything in it, becomes one file where it was: Photos becomes Photos.olock. Nothing of what is inside shows, not even the names of its files and folders: anyone who finds it sees only that file's own name, its size and your hint. When it is unlocked, its folders, file dates and read-only files come back as they were.
The key is made from your password with Argon2id, using 64 MiB of memory and 3 passes with a new random salt each time, which is deliberately slow so that guessing passwords one after another takes a long time. The folder is encrypted with XChaCha20-Poly1305 and a 256-bit key, in 1 MiB pieces that are each checked when it is opened, so a locked file that was changed, damaged or cut short does not open, and Octoolo says so.
Before you lock: no password, no way in
Octoolo keeps no copy of the password, there is no account to recover it from, and nothing is uploaded. If it is forgotten, nobody can open the folder: not you, not Octoolo. Write it down, or keep it in Passwords; a long passphrase from the password generator is hard to guess and easy to keep there.
The original folder is removed only after the locked file has been read back whole and compared with what went in. A file in the folder that is open in another program stops the lock before anything changes, and if something could not be removed afterwards, Octoolo lists it. The original is deleted rather than sent to the Recycle Bin, which would keep an unlocked copy; deleted data is not reliably overwritten on SSDs, so the lock protects the folder from now on but is not a way to erase every trace of the old one.
Octoolo or an online tool?
| Detail | Octoolo | A typical online tool |
|---|---|---|
| Your files | Stay on your computer | Usually uploaded to the site's server |
| Without internet | Works | Does not work |
| File size | No limit | Often capped on free use |
| Watermarks and ads | None | Common on free plans |
| Cost | $4.99 a month, all 17 apps | Free with limits, or a plan per site |
Questions, answered
Can I lock a folder in Windows 11 without extra software?
Not with a password of its own. Windows Pro, Enterprise and Education can encrypt a folder for your Windows account with EFS, which Windows Home does not have, and BitLocker encrypts whole drives. Octoolo locks a single folder with a password on any edition.
What if I forget the password?
Then nobody can open the folder, Octoolo included: there is no reset and no copy of the password anywhere. The hint you add is there to jog your memory.
Can I lock my whole Documents or Desktop folder?
No. Octoolo does not lock a whole drive, Windows' and programs' own folders (Windows, Program Files, ProgramData, AppData), your user folder, or your Desktop, Documents, Downloads, Pictures, Music and Videos folders themselves. The folders and files inside them lock fine.
Does it hide that the folder exists?
No. The locked file keeps the folder's name with .olock after it, so people can see it is there and how big it is, but not what is inside or the names of the files in it.
Can someone still delete a locked folder?
Yes. A .olock file is an ordinary file: anyone using your PC can move, copy or delete it, just not open it. Keep a backup of anything important, locked or not.
Why will a folder not lock?
A folder with links or junctions inside is not locked, because they would not come back as they were. A file in it that is open in another program stops the lock until you close it there, and the disk needs room for the locked file beside the folder.
Lock a folder, and 16 more apps.
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