If you don't have word processing software on your home computer you can safely download Open Office for free at http://www.openoffice.org/
Open Office even allows you to save documents in .doc or .rtf format so that they can be opened by the Microsoft Word program. This way your child can start an assignment at home, bring it to school on a flash or thumb drive, and finish it in Word at school! It's great and it's TOTALLY FREE!
It would also be useful for parents who need to bring work home with them occasionally.