Hi there, don't reboot now. Just try these, hope after that you didn't face this problem again. Please follow the steps.
1. Restart the PC and repeatedly hit F8 until you have a menu in front of you.
2. You will find few option there. Just select these mention option "
Last know good Configuration ...." use by your up/down arrow on your keyboard.
3. Press
enter there.
4. your will see the system asking you for which OS you want to use. If you have only one OS then just press ENTER there or select the OS and Enter.
Now your laptop start booting. Hope, now you not faced the message. If you not satisfied then ask me. I am ready to solve this problem.
Thanks & waiting for your feed back.