Avast Pro Version - Avast web site claims it supports VISTA 64bit???

[Rodv1967]

then why doesnt the schedule boot scan work, it's greyed out, I just bought the latest version of Avast Pro for my 64bit HP desktop, for 2 years and I cannot enable a boot scan in the program, function is greyed out, this is a rip off!
rodv

[DavidR]

Because it currently doesn't work with 64bit OSes.

The boot-time scan works in the 32bit OS (avast being to only AV that can do this as far as I'm aware), but it is more complex in the 64bit OS and Alwil are trying to find a way. So the only other option is to boot into safe mode and run a scan from there.

[Reductase]

...this is a rip off!...

While it isn't mentioned on the overview page for Avast (which would be helpful), I guess you missed this section under System Integration:

"A new option in this release is the boot-time scan (Windows NT/2000/XP/Vista 32bit only). This important feature allows a user to instigate scanning before a virus is activated, in the case that a virus is suspected to be active on your computer already."

http://www.avast.com/eng/avast-4-professional-antivirus-antispyware.html

Also, it is usually a good idea to take advantage of the trial periods for software (60 days for Avast!) that are offered prior to buying.  I think you will still find it works well for x64 overall though.