regarding my dell 720 injet printer

I have the 720 and everything was fine until my hubby decided to type foot notes and what happend from there i dont know. he dosent really know much about the computer. and he has been trying things the last time he tried something he got me a virus (trojan)  so i told him to please please stay away from what you dont really know about and in the printing department i dont know either. well i went to print something it said that there printer cant be read so i went to make sure it was not paused or anything then i tried again and said there is not hardware set up for this well any way i was told by wizard to download something? like i said I am not good with printer either, but when i print it isnt anything its a garbled mess. it looks like it trying to print a  face and cant. i have ink and its fine. i found my cd from dell do i just go to add/remove and delete the old stuff and just put the dell cd back in to make it as if when i brought it here?  thanks