Donna Fowler This software is offered with a free version already. They do have a pro-version that has a cost. The software is designed for corp. use. The reason they carry a free version is that they offer it to their corp. account employees so that they are less likely to infect the corp. account computers when bringing a usb or flash device in that would bypass most security systems. I have been using it ten years and have always had great success in all situations. My favorite feature is the boot time scan that looks for viruses before the operating system loads and this allows for removal of the infection before it can start counter measures keeping antivirus programs from doing their job. They also have a mobile edition in Google Play store. Not sure about the mobile app for other ois's.