Boot failure error in Dell XPS 9100

Hello,
I am using Dell XPS 9100 with Windows 7 operating system and it worked fine till now.
From yesterday, it has kept getting stuck and after booting I am unable to see the desktop icons but the toolbar is present. I have rebooted several times and most of the times the reboot is failing and asking to press F1 to Reboot again. Also, I am feeling that the CPU fan sound is more than normal.
Why it is happening? What is the problem? Is this a problem with BIOS? Any suggestions will be very much appreciated. Thanks in advance.
