Why my Windows is showing unknown setting messages?

Hi guys, I have windows 7 and since 2 months its showing "do you want to set these settings as default yes or no" what it is I did not make any settings or changes to my PC but still it shows this message every time I open it and nothing happens if click on Yes or on NO again next time when I open PC again it will show the same message.What is the problem?? I don't know please help me fix it
