Password protecting an external HDD?

[Comp625]

I just purchased a 200gb hard drive and a separate external enclosure. I was wondering if there is any way to password protect the HDD so that if someone were to plug the unit into their rig, they wouldn't be able to see the drive's contents.

 

[Cristatus]

I'm betting that's it's pretty hard to do, if it's possible.

My approach would be an encrypted file system, but I'm not sure what OSs you will be running your drive with.

 

[Comp625]

It'll be your everyday Windows XP as I don't really mess with other OS's