Hi! Yesterday, I found a strange file in my Word. I was straightening out my files, when I found a strange file. It had extenions of .sf. When I hit the file, my computer went crazy. It start blinking a white screen off and on for about 5 minutes, a bunch of icons kept coming on the bottom of the screen. It really scared me so I manually turned the computer off. What would cause this. If I wish to buy new anti virus software how can i get Discount Coupons on Anti virus software?