DEACTIVATE WEBSURFING W/ E-MAIL FUNCTION

I am planning to deploy Outlook Express as e-mail utility in a desktop running Windows 98SE in our warehouse to receive email from the head office. In order to discourage employees from doing unecessary websurfing, I wish to know how to disable surfing capability either from Windows Explorer or IE in Windows 98SE altogether without necessarily disabling e-mail functionality. Can this be possibly done? I don’t intend to use any third-party software to enable blocking.

Your inputs will be highly appreciated.

Thank you very much.

FRANCIS