if it came from someone else the best thing to do would be to use the recovery option when you boot and wipe it even if it came from a family member. Just save the photo's etc.. then wipe, I don't even give advice past that if someone else used it before, you have no clue what she could of clicked on etc... To many people think everything is perfect and safe for them once their AV or other tools detect something and fix their problem. But it really isn't all that hard to bypass AV, AV software is way behind as far as what the slandered user would actually need to stay protected.