Can I lock Drive?

Guy's I am using Windows XP sp2. I have the gunine version of it. I have created 5 patition of my hard drive named C: D: E: F: G: in the G: I stored my personal data. My all family members use my computer and I don't want to show my data infront of them. I want to lock my G: with a password to protect my data. Is it possible? Isthere any method or any third party software for do this please tell me.

Thanks:

Alex_tom