Nah; MSN Explorer is not IE - it is based on that technology but a completely different Microsoft Department Makes it - it is far safer than both Mozilla and certainly Internet Explorer. (Read this if you don't believe that)
It is worth the money; you also get Encarta, Photos a Download Manager, Members (so if you search for things you don't want the parents to read; it doesn't have the same account so the searches aren't listed
Parental Controls if the above scares you that your son/daughter could be doing that, a toolbar, Address Book, many advanced features including a highlighter; and advanced E-mailing including POP3 Account Access.
Gets nine point nice thumbs up from me!