Background:
Been away from BIAB products for a long time.
I own the 2009 version supplied on an external hard disk...
"entire Band-in-a-Box and RealBand EverythingPAK on this portable USB 2.5" hard drive"
I also have Powertracks Po Audio 9 CD and theRoland VSC CD.
Goal:
Connect my M-Audio Axiom 49 keyboard controller and create some tracks for a project.
The Questions:
1 - If I remember right I did thie years ago, on another Windows PC, using PowerTracks and the Roland Virtual Sound Card.
Is that still the way to go?

2 - If I upgrade BIAB I see the VST DAW Plugin... but that requires more software like Cakewalk or some other DAW... right?

3 - I could upgrade to the latest PowerTracks but I'm confused if PowerTracks is a full fledged DAW. Is PowerTracks a true, fullly functional DAW by todays standards? If not what DAW should I consider.

4 - Will the PowerTracks ProAudio 9 CD and the Roland VSC CD software install on my Windows 10 PC or must I upgrade for this project.

Thanks for any help. I've just been away so long I'm just like a newbie :-)

I'll answer you questions the best that I can:
1- Yes. That is one way to go.
2- Yes, but if you use Realband you don't need the VST
3- I do not know as I have never used Powertrack Pro.
4- Maybe but I don't know. You would have to contact Roland and PGMusic to be sure.

If you upgrade to the latest BiaB you will also get Realband. Realband is a DAW. For many here on the forums it is the only DAW they use. You will not need the VST version if you use Realband.

Personally if I were you I would upgrade.

For #3 I’m not sure anyone would call PowerTracks a ‘full fledged DAW’ by today’s standards. RealBand is closer and was developed from it.

About what DAW to consider, if price is a concern, try Cakewalk and Reaper.

Ideally, download demos and try them all. Buy the one that you feel matches your workflow and seems most intuitive for you.

Will.
its a difficult question to answer unless you go into much more detail of your budget and needs.
even though i use biab/rb/reaper combo to create songs , as an old powertraks user i think powertraks is a steal of a deal for a daw.
as your an old ptraks user i think you can upgrade to latest version for the princely sum of 29 buks...a steal imho.
check with pg sales. imho haveing used lots of daws both powertraks and realband are great daws.
but so too is reaper imho. its 60 buks. also there are lots of free daws like cake and traction etc.
all very very nice.

there are many other ways to go viz pg products.. see the pg sales page for the various options/upgrades etc.
from under 100 buks to several hundred buks for all the real traks etc.

imho if all george martin and the lads had was powertraks
with its 48 traks they would still produce worldwide hits.
we are spoilt today for options...lol

best/ymmv
oldmuso

'Virtual' Sound Canvas is likely not going to work anymore. (Question 1 & 4 of OP)
At least not the one PGMusic supplied in years gone by.

There are others out there, and Sonar/Cakewalk comes with a nice one that *can work in other DAWS. Some people have installed Sonar/Cakewalk just to have the synth, and that's not a terrible option so far, given it's free.

So, just to be clear...

a. the new BIAB comes with Real Band DAW... so I will not need an extra program like Cakewalk... right?

b. Also, will BIAB with Real Band record me playing the M=Audio Axion 49 midi controller... so I don't have to first record my playing into PowerTracks?

c. And, if so, will it record my keybord in real time while I'm listening to the other tracks?

Thanks again for the help.

Well, if recording MIDI from the controller, yes, for sure. Vouching for RB here.
If you have RB, you already have Powertracks and then some ..

Is RB a DAW? Well yes, it does most of what other DAWs do, and some things others can't, but it has its own rules/workflows.
If you are not already use to another DAW, you'll be fine.

I find that quite often, I don't really 'need' the other DAWs I have, RB does what I need, just a different workflow.

If trying to record Audio from a controller, you are going to have to learn Routing in any DAW.
The benefit of having Cakewalk (which is free BTW), is that you now also have the TTS-1 synth, which RB and other DAWS can use.
Peter Gannon (the 'PG' in PGMusic) made a 'No Brainer' post on obtaining this synth (recommending getting CW just to have it) so you can have a decent 'default synth'.
So I'm guessing a lot of the staff use it as a default synth also, but this is just conjecture on my part.

I have a few hardware synths with GM patch options, so I feel fine without it so far, but that's just me.
Basically, yes, if you have Realband, you do not need Powertracks at all (Realband development/updates happen before PT historically; PT gets the upgrades RB already has later in the year) .. again in recent history anyway.