Hi, brightsun.
That is a completely different situation, and certainly not attributable to either Firefox or AVG. I can only take you so far with this and then a hardware expert will need to take over. However, let's get some basics down.
It is
important that you respond to each question and follow each set of instructions in the order provided.
EDIT NOTE:
I just learned that again there is a
serious problem with LinkScanner component. Technically, it is a form of HTTP hammering with the impact depending on how many users with AVG 2011 access a particular site. That aside, as suggested by
Softpedia, browsers will open tens or hundreds of connections in the background and will become unresponsive.
As a result of the above information, if you have AVG 2011 and LinkScanner installed on your computer, stop at this point and go back up to my earlier instructions and proceed with removing AVG installing MSE.
Please confirm when you have removed AVG and installed MSE.
(Previous instructions removed in lieu of the newly learned information regarding LinkScanner.)