+1  A: 

There's a good example on how to encrypt/decrypt files using vb.net on codeproject.com http://www.codeproject.com/KB/security/EncryptFile.aspx

xenosyde
wow thanks for posting that article! I just read it... I think I am gonna just try my own type of 'fast' encryption. But the techniques he used were very informative. Thanks
Dooms101
+1  A: 

Well... .NET includes A LOT of security and encryption classes. I would begin your search by looking in the System.Security.Cryptography namespace.

If you need help implementing a specific method from within the options there, let us know.

As a side note, you should be able to handle all of your file access from the System.IO namespace. Try to stay away from the Microsoft.VisualBasic namespace as a lot of the stuff in there is no longer best practice.

-edit: Typo.

Sonny Boy