Note: The built in Windows compression tool cannot password protect a compressed file; therefore a third-party application has to be used. In this article we use 7-Zip utility which is licensed under the GNU LGPL/GNU LGPL + unRAR and hence is free to download and use.

What to do

1. Download the 7-Zip installer for your computer from www.7-zip.org. Run the program and install 7-Zip to your computer.
2. In Windows Explorer, browse to the file you want to compress with 7-Zip.
3. With the file/files/folder highlighted right-click on one item and from the sub menu select 7-Zip > Add to archive….
4. If you are sending the file to another person, who may not have 7-Zip installed, change the Archive format option from the default 7z to zip.
5. Under the heading Encryption enter a password in the first field, and reenter the same password into the second password field. Ensure you do not forget the password you entered as you will be prevented from opening files inside the archive in the future.
6. You may now click OK to create the compressed archive.

Note: Not all compression programs can open archives protected with AES-256 encryption so the recipients may have a problem opening the archive, or you may have a problem opening the file on another computer. Consider the level of protection required for the files and select the method of encryption that is appropriate.

• Either leave the Encryption method as ZipCrypto to maximize compatibility with other compression programs. If you are sending the file to another person their compression program will most likely open .zip files encrypted with the ZipCrypto standard.
• Or change the Encryption method to AES-256 if you need maximum security protection for the file/files/folder contained inside the archive.

You will have a new file with a .zip file extension in the same folder as the file/files/folder you selected to compress in step three.

If you open the zip and then try to open a file inside the zip file you will be prompted for the password you set previously.