It is a new feature in AVG 2012 called AVG Advisor - you can turn it off in Advanced Settings-> Appearance -> "Display AVG Advisor performance notifications".
It could be because of IE add-ons. It can happen when the RAM of the PC is relatively small compared to the size of programmes installed.It is referring to virtual memory rather than RAM - have a look at this article which explains it.
It may be a good idea to try to reset your IE settings - I assume you have IE9 - have a look at this article on how to do this. This will return your IE9 to how it was when first installed and your present settings will be lost.