hey all, my sister had the same problem with a laptop running vista and lost her antivirus. never did figure out why it just uninstalled itself. she did however reinstall it and has had no problems since. not sure what to tell you, i would run malwarebytes and microsoft security scanner and see what it finds. try reinstalling the antivirus software and see what it does. are you using any registry cleaners because some of them can and will remove things that you don't want removed. i would also try searching my hard drive for any avg software that was installed to see if it was still their but may be hidden. thats a rough one to figure. thanks. poorguy