@Elle if it's on the bottom of your computer it is safe, as Java has recently updated so the one you are seeing is genuine. The ones to avoid are any pop-ups that claim that your computer is running slow or offering updates that you should avoid, don't even click on the X to close as it can be a way for malware to install by stealth. Make sure you have a pop-up blocker running, it will deal with most problems of this nature.