Start IE on the Tools tab, top right of the browser bar click Manage Add-ons and then on the Window that opens disable most of them.
I think you will find you are running an out of date JAVA - check for updates and in any case disable the Java helper, disable the Search Helper it is unnecessary, disable Windows Live sign in helper, disable adobe pdf link helper at the very least.
I agree that the problem may be AVG. I presume as you say you upgraded it is the paid for edition.
When did you last clear the temp files etc on IE8
Download this and run it. You may check all boxes BUT BE AWARE that it will delete any saved passwords for sites, not the Windows passwords and it will not effect your favourites and bookmarks
There is no concern regarding your chkdsk results.
Please post back a closing remark, as you consider appropriate, please do not just leave the thread.
Edited by Macboatmaster, 03 October 2010 - 12:02 PM.