Start up problem

I turn on the laptop & this is the message I get:
We apologize for this inconvenience, but Windows did not start successfully. A recent hardware or software change might have caused this.
If your computer stopped responding, restarted unexpectedly, or was automatically shut down rto protect your files & folders, choose last know good configureaction to revert to most recent settingins tha worked.
If a previous startup attempt was interupted due to a power failure or because the power or reset button was pressed, or if you aren't sure what caused the problem, choose start windows normally.

(Opitions given to start computer)
Safe Mode
Safe Mode w networking
Safe Mode w/ command promts

Last know good configuration(your most recent settings that worked)

Start Windos Normally


** I have tried all of those opitions. However it still won't start up! I am fed up with it. What can I do? Or Do I need to buy a new part?
What I need it to work so I can get more things done during the day!!!!
Thanks for any help!