Here’s how to password-protect a folder on Windows 10:
Navigate to the folder and make sure all files you want to encrypt are inside.
Right-click on the folder and open Properties.
Under the General tab, click Advanced.
Check the “Encrypt contents to secure data” box.Encrypt contents to secure data
Choose “Apply changes to this folder only” and click OK.Apply changes to this folder only
Backup your encryption key when prompted.
When I follow these instructions, the option "Encrypt Contents to Secure Data" is grayed out, and I can not check the box. (I can only check the box to compress the file.) I have tried on the regular file and on a zipped file. Neither allows me to encrypt. ???