I used both MaCfee and Norton scan the computer, nothing found. I really don't think it is caused by Virus, I have had many virus attacks before (on other computers), they always send a warning screen to me and told me my computer has virus now and ask me to purchase their software to clean it. Not this time, everything runs find if I don't change the system/parameters, there is no benefits to those hackers in this case. I am thinking may be there is a system change bit needs to be turned on, or I may not have administrator Authorization, etc. on that line....The only thing I messed around lately was the MaCfee security software which came with the computer on day one, I turned some those features on or off, etc...did not change anything else, never download anything from internet either...I searched Macrosoft Support, found lots of hits on that error message, but none seems apply to my case (or I should say, I do not know which one apply to me)..But I still think this is a simple system setting issue, hope some one had this problem before.