I bought a CD containing SP3 from Microsoft. <g>
But OS version does not affect library use with respect to
most software. There are libraries that come with language
compilers, which are separate products from the OS. (And
which I don't use anyway, since Daqarta is 100% assembly
language.)
Then there are DLLs that are part of the API for the OS, but
which are upgraded by the *users* on their own systems. An
app can call a standard API function (say, to show text on
the screen) and let the OS do the rest. It may be that the
newer OS version uses (say) better graphics acceleration for
the same API function, but the app doesn't need to know
about that. (And probably shouldn't, and usually can't even
if it wanted to.)
And if there was a security problem with a particular API
function on the old version, simply running the app on the
newer version completely solves the problem.
But in case you are still concerned, note that if you
download Daqarta from my site you are guaranteed of getting
a digitally signed version (which can be verfied from within
the program to prove it hasn't been tampered with), and that
VirusTotal has tested it on the latest versions of over 40
different anti-virus packages and passed it with flying
colors.