HELP...cursor jumping all around document

I need help, Please. When typing a document whether in Word or in Outlook Express the cursor jumps to other areas in the message and inserts the text being typed there or suddenly portions of the document highlites itself and just goes crazy or as I type, suddenly from the place I last saved it, all the text disappears and I am unable to get it back....another thing is very often the cursor jumps completely out of the document into the toolbar, etc. What in the world is going wrong? We just installed Windows Live One Care....I can't type without watching the screen and stopping constantly to correct what is being done without me doing it....Please Help...Thank you, Deb