AxCrypt offers a simple, free way to encrypt individual files. Right-click a file, a few files, or a folder, select an option from the AxCrypt submenu, enter a password (you can save a default), and the file becomes inaccessible to those not in the know.
You can simply encrypt the files, turning each one into an AxCrypt-associated .axx file, encrypt a copy to an .axx file, or encrypt a copy to a self-executing .exe file--handy if you're sending it to someone who doesn't have AxCrypt. Actually, that feature'snot as handy as you might think. Many e-mail systems won't allow you to mail or receive .exe file attachments, making it tricky to send to others.
You can also use AxCrypt to shred a file, overwriting it with random data so it cannot be retrieved. But it's a simple shredder, without using the more complex secure delete algorithms found in programs like Eraser.
Speaking of algorithms, AxCrypt uses 128-bit AES encryption, and doesn't include an option for the presumably more secure AES-256. But according to a report by security expert Bruce Schneier, AES-128 is actually more secure than AES-256, although neither are really breakable in any practical sense--at least if you have a strong password.
AxCrypt provides something for people who don't bother to create a strong password. You can let the program create a Key-File, is a plain text file containing a very long and random string of characters. You therefore don't have to remember the password; you just have to avoid losing the Key-File--and take care not to let the wrong person get their hands on it.