Lock down C: drive partition in Win NT

Is there a way to prevent users from loading anything to the c partition on a 2 partition drive. I partition the drive with 2gb c partition and all the rest of drive d. I continue to get users that copy files, downloads to the c drive and fill it up. Then I can’t load updates or the pc locks up. I keep telling them to not load anything on the c drive, but some do not listen. Help!