Barb, in the taskbar at the bottom of your screen, to the right hand side you should see a little square for AVG, if it's out of date it should be grey??
Double click the icon, and a box will open, when the box opens to the left there is an option "check for updates" click this, anther box will open you need to tick a box "internet" to download the updates from the internet, it should downl;oad all available files for you, then wehn it's done you click a box "OK", you should then see the AVG icon in your taskbar tray turn coloured again. The problem here is your so hasn't turned automatic updates on, so you need to smack his bottom and get him back to do it for you!!!