No Way to Access BIOS Setup in Sony-VAIO

Somebody please tell me what to do. I can’t access BIOS system of my Sony VAIO EA24FM/W.
I am trying to access BIOS by pressing the function keys including Esc, Del, Ctrl + Esc & Ctrl + Del, F1 but nothing is working.
After showing the VAIO logo operating system starts loading.
While I am pressing Esc, it reboots the computer. I am running Vista and want to install Windows 7.
Only F8 key is working which says to choose safemode and other options also available which are not related to BIOS.
Is this a virus case or any kind of damage occurs in BIOS?
All the Sony-VAIO users please help me.
