If you share your PC, and want to protect your files so no-one can access them, you can do it with Smart Encryptor. It is a small program that lets you password encrypt all types of files and folders. This way, you can be sure of, among other things, sending files via the Internet safe in the knowledge that only the reciever can open them.
Also Smart Encryptor, for better security, uses two advanced algorithm encryption services: AES (Avanced Encryption Standard) and Blowfish (cyphered with 64-bit blocks and keys of up to 448-bits). All this so that encrypting files is quick, compact, simple and safe.
And if what you need is to work with a file that has already been encrypted, but your PC doesn´t have Smart Encryptor, you don´t need to install it, as it has an autodecompress system. Just double click on the file and insert the password so you can open it. Smart Encryptor also has an option that lets you delete the original files once they have been encrypted for better security.