How to Write-protect a section of portable hard disk?

I have a large capacity portable hard-disk (Western Digital 2 TB / NTFS file system / Win XP)

I plan to put the complete collection of videos, music, movies, etc. that I have on this disk.

I also plan to share this drive with a few of my friends—so that they take it home and can copy the stuff they like, and also add new stuff from their own collections to this disk to share with me.

Now, I want to ensure the integrity of the data I load on this disk—do not want any data to be deleted or moved by them by mistake.

Can I write-protect a section of the portable hard-disk?

I could create one root folder for all my data and mark it read-only. Will this be enough?