blackknights

Greetings all yes another newbie here at MSFN although must say a very informative site. My question is this is there a product or way to lock certian files that I am the only one able to view them. I understand that by using Winzip or Winrar I can compress the file of choice and password protect it but what I'm looking for an app that will allow me to enter a key to view the original file. Any thoughts and thanks in advance After thought if needed my OS is XP Pro Blackknights B)