Hi, I have got a desktop with windows 7 operating system installed in it. I am currently using Microsoft security essential and I found it to be very good for my system. I have also got Norton antivirus software. But I canít use it now, as Microsoft security essential is installed. I also want to use Norton antivirus as I paid for it. But I came to know that two different Internet securities should not be used. Is it true. What will happen if I install both of the security software. Can anybody have any suggestions regarding this.