I do not have that option in my BIOS. It seems to me that i only have a very limited BIOS anways. THe only settings i can change is basically the system time and date and the boot order. (it is called Phoenix securecore)

I shut the computer down 2 nights ago after using it regularly (surfing the internet, checking my mails) and then i couldnt boot it anymore the next morning.

thanks alot for your help !