Black screen

Registration date
Saturday September 13, 2014
Last seen
September 13, 2014
I have dell inspiron N5050 ,when my laptop was well operational I did some changes in vlc media player because vlc player was asking promt permmission to start vlc player , I did changes and it worked , double click and media starts without any promt permmission then shut down my laptop and started again , but when I started my laptop everything was normal, after starting dell logo appeared and then it shows Windows wete not shut down properly , so i selected start Window normally , coloured welcome logo appered n then it turned black screen and still it 's same . Please advise what shall I do ?