If you want to stop people accessing a file or folder, encrypting the file with a password is a great way to do it. First either open Archive Manager and click New, or right-click on the folder you want to protect and press 'Compress'.

Then chose a compression format you can encrypt (e.g. .7z, .arj, etc) _{(under Other Options)}. Using 7zip compression is good, as then you can encrypt the file list to. Then type the password you want to use.

Then you can add files:

Then you have an encrypted archive with your files secure inside - though it can still be deleted...

You can also hide the compressed file by adding a . to the beginning of the file name, so it only shows when you press Ctrl+H.