I remember reading somewhere that this version of SAM only runs on single core/32bit O/S.
It's not that SAM only runs on single core / 32bit CPU, but that SAM will only make use of a single core and the 32bit interoperability layer of your OS.
Until MS decides to turn off 32 bit support (keep in mind, so far they haven't even switched off 16 bit DOS-Software-Support, so I reckon it'll take another 30 years before they reach 32 bit deprecation) 32 bit software will keep running just fine (if a little bit slower than their 64 bit counterparst, but that is usually more than made up for by the more efficient CPUs these days)
And as 4.x is no longer supported, that's also where this support journey ends on this forum. Feel free to look in more generic internet broadcaster forums or user groups on Facebook etc. if you need more in-depth support with a 10+ year old piece of software. There might be some nostalgics around there.
Or bite the bullet and upgrade once every 10 years. It's dirt cheap at ~30 USD/year if you can hold out that long.