E6400: How to disable boot sector write protection?

Hi,

I have a E6400 and cant install XP. After booting from CD, and loading all the files for windows setup, it gives a bluescreen error suggesting there is a virus. My most likely explanation is that the boot sector is write protected. However, after browsing all of the tabs in BIOS (version A17), ive not found any option to disable this. Can anyone point me to the location of this option?