My computer crashed after I once shut it down. It says that My harddrive is broken and that I have to replace it and press F1 to continue. Before it shows the message it starts fine, but when I press F2 to enter BIOS, nothing happens. It doesn't even say "Press F2 to enter BIOS". Can't you boot from a USB or CD even if your harddrive is dead? When I say boot, I mean install an OS on a different harddrive located inside the computer?
So what is it, a broken harddrive or a virus inside BIOS?
Yes you can boot from CD or USB when the drive is dead. Remove the SATA or IDE cable going to the hard drive to make sure the machine works without it. If the motherboard "sees" the dead hard drive, it may not boot properly. At least that has happened to me multiple times.