Optional Update question

I am getting notification of an optional update that I haven't installed
yet, saying:

"CTX - Modems - PCI Soft Data Fax Modem with Smart PC"

Regarding the above, I have the following questions:

1. When I get such notifications in "Optional UPdates", does Vista already
scanned my computer and determined automatically that my computer might need
and could use this update, pending on my installation approval?



2. Or, do I have to determine manually myself if I have the compatibe
software to install this "Optional Update" and do I have to determine myself
if I need this update? I really don't know how to determine that. If I
have to determine that, how do I do that?


I have been able to determine and also installed the others that I got
after installing Vista Ultimate, but I don't know what this one referenced
above is about.


Thanks in advance.