Boot Virus Detection option in CMOS

[jagnorm]

I have ASUS A7N8X-X
In the cmos setup options there is an option for Boot Virus Detection.
My question is will enabling this option Stop a virus from entering boot sector if computer is left on line and i'm not near it? Or will it just beep give warning while virus makes it way through.
I have nortons AV 2002 which in the past has told me whether boot sector has been changed and asked whether I want to save the changes.
By default it is disabled.
Should I enable this option.
Will it slow my board down any?

[nukes]

It will just stop anything writing to the boot sector. Virus or not. Few modern virii write to the boot sector anyway, as there's much better ways to hide away inside windows itself. It especially helps the internet worms, which would have hardly any way to propogate without windows.
My advice is just to leave it off. Its not going to help you any, and will cause you trouble if you need to re-install windows or something. Plus reinstalling windows is a lot more likely than getting a boot sector virus.

[jagnorm]

Thanks for the advise. I'll leave it off...