Actually, despite its brevity, Hal's post is correct, although he may have made a few assumptions based on your post, just as I will in this post.
First, the existence of an "intern" and a "network" presume some sort of institutional setting, and hence, the existence of a system administrator in charge of all things associated with the network. Contact that person to see what is required and allowed.
Second, if you are on a local/home network and you want to share, go to Preferences>Sharing and see what is available to you.
Third, if you are really saying you do NOT want the intern to have access and you're wondering if Windows PCs have mystical abilities different from the Mac in this area of concern, don't worry. Trust your intern and know s/he won't be snooping around your Mac.
Fourth, if "second" above is correct, what the PC machine will have to do to share with your Mac is unknown, at least to me.
Fifth, if none of this makes sense or you mean something else, post again.
