Of course but it leads me to programs like bitlocker or truecrypt which is high level security. All I am trying to do is a simple password so I can keep kids out of the drive. While I make monthly back ups via DVD I like to have digital copies of all transactions of the past 20+ years.
With most solutions though it seems to alter the files making it unusable on other systems or is so tedious that I would turn it on and off 10-12 times a day to keep the info safe. I work at home so I am up and about a lot.