Laptop not starting

I have a dell vostro 1540 laptop . Few days back it was working properly and suddenly it closed .when i tried to restart it , a msg was displayed while starting that window is recovering.i thought that it happened due to improper shut down which i have seen most of the time but it suddenly stopped in the middle of it and when i tried to restart it which is not working .yesterday again i tried to start my laptop n this time it worked n the window was booting and the same msg appeared that window is repairing and then window is diagonising.but again it stopped and i am unable to start it now.Everytime i tried to put on the power it gives a beep sound n then no result.i tried reading on this forum about battery drain but it is also in vain.kindly help me sort out my problem.