From extoff to other reasons, look over prior discussions like http://social.technet.microsoft.com/Forums/en-US/itprovistaie/thread/53a3b82c-e61a-4576-8d80-91e204d4b1e9
There are many other discussions about this.
My solution is simpler. I don't use IE.
I have been having a reoccurring problem with my second PC it seems that when I bring up windows explorer, I can go off to any specific web pages due to the fact that ny Add-Ons have been disabled. First how did this happen? I really don't think that did this, anyway how do I turn these Add-Ons back on???