See if when you download it it says anything about TWAIN either in the
Readme or on the website. If it does, VISTA does not recognize scanners
using TWAIN to talk to the computer so the scanner will not show up in
FAX & SCAN if your version of VISTA has that feature. From what I can
see it is likely that your scanner does use TWAIN since they explain
what it is.
What I found with my old HP SJ5P scanner is that if I installed the HP
Deskscan 2.9 scanning Utility (for HP's older scanners) then the
scanner was recognized by the utility and could be run from that
application.
I was also a little surprised that it also appeared in MS WORD and in
Irfanview graphics utility with a Scan to menu entry!
So look for imaging software (ScanPanel?) that may have come with your
scanner and try installing that using Compatibility mode and Run as
Administrator -- you can do that by selecting the file that starts the
installation of the software by right mouse clicking on it and
selecting the Compatibility TAB where you can select, for example, XP
with SP2 for VISTA to pretend to be and check the box at the bottom for
Run as Administrator.
How is the scanner connected to the PC? If it's USB follow the makers
instructions which may say to only connect the cable to the PC after
the software is installed; or it may say do it first -- look for this
since it can make a difference.
Good luck