Boot Scan option blanked-out

I have a registered Avast 4.8 Home edition for antivirus.
My OS is Vista Ultimate 64.
I’m trying to schedule a boot time scan but that option is constantly blanked out.
I have uninstalled/reinstalled Avast but the problem remains. Help!! ???

The boot-time scan isn’t available on 64bit OSes currently, I believe they are trying to get arround that but currently not available.

The only scan outside of normal windows would be from safe mode, assuming that is available with Vista64.

Is there a particular reason why you need to schedule one ?

All of a sudden MSN doesn’t work on my Vista PC and www.digg.com will not load (but it loads fine on my XP machine sharing the same network). I suspect a virus or something has interfered with port settings and I want to boot scan to nip anything on my PC in the bud.

David already answered that this is not possible with 64bits…