Dear All,
I just noticed that Ad-aware is an effective tool to repair IE problems, such as melicious change of default website and so on, actually this has been annonying me for a long time, those recommanded tools by some network experts can never exterminate the problem in my computer. But now with help of Ad-aware, I successfully fixed it. If you have such problem, just try it. However,whether it works or not deponds on your real cases. Here I just want to say it might be a solution, and once it works, you will found it great!