laptop dell n5010 - problems when booting up

Hello, a friend of mine owns a Dell N5010. He is using Windows 7. Recently he updated the BIOS to the latest version available, and since then he's been experiencing problems with his laptop. Most often, his laptop shuts itself off during bootup or system restart. What could be the reason for that problem and how could this be fixed ? Is there something that should be changed in the bios configuration or any way to reestablish the old bios version ? Thank you all for your replies.