I've recorded plenty of 12 track recordings back when 1 Gig was max with XP. It was the drivers and the Interface that facilitate recording audio and a 100GB 7200 RPM hard drive was the ticket in those days.
So if your running W XP and only have 1 GB RAM you certainly can record 12 tracks of audio. But of course you won't be doing anything on a W10 or even W7 with 1 GB of RAM that is not a real world case scenario. That computer will have at least 4 GB and would work just fine for 20 + tracks of audio ( done that)
8 GB is the norm for even an office box these days.
Your average DAW uses 16 or more GB's even if we don't need it, it's nice to know it's there.
You say you built your Vista machine. Have you thought of building the new one? Lots of stuff on sale right now and you should be able to build an i5 for around $600 with solid first class hardware in it. Off the self computers are like Walmart home stereo's to me.
I was just given a 2 year old HP i7 box that cost $2,000. Compared to the the 2 I built about the same time for less than half of that it's a cheapo machine inside. 125Watt PS?? Pour quality RAM ( only 10GB) I seriously was going to make it my main DAW because the processor is i7 and mine is i5. There was no noticeable difference when rendering audio etc so I'm staying with the one I built. I actually don't know what to do with it now as even my office computer is better built. I guess I'll see if someone in the family needs an upgrade. But I'm convinced the way to go with a DAW is build your own, OR buy from a custom builder.