If Acer/Benq has no driver you can use VueScan from
http://www.hamrick.com/vsm.html
"Perplexed" <Perplexed@discussions.microsoft.com> wrote in message
news:47F6BE1E-3219-4BF5-9686-53C55083EFF7@microsoft.com...
>I have an Acer 640BU scanner that I am unable to find a driver update for.
>I
> am using Vista Home Edition. Any suggestions??