Installed 10 last Summer - 8.5 works well  (only tried it 64bit flavour though).

I was mistaken, sorry. My windows 10 partition does not has 8.5 on it but it does have the SONAR 5 (yes FIVE) Producer edition demo on it. And that runs like a champ. 

OK, great this is what I needed to hear, win 10 and sonar 8.5. Will give it a shot.
 
The new pricing scheme of monthly update payments is not for me, looks like the end of the road for cakewalk in my world, no worthwhile upgrades either.  I own versions 1 to 8.5. 

kirksonardate
OK, great this is what I needed to hear, win 10 and sonar 8.5. Will give it a shot.
 
The new pricing scheme of monthly update payments is not for me, looks like the end of the road for cakewalk in my world, no worthwhile upgrades either.  I own versions 1 to 8.5. 

That is only one option. You can do as you have always done and buy the new version each year or so. For me I pay nothing because I have lifetime updates. You could have had that too. Plus Sonar Platinum is as superior to 8.5 as 8.5 was to Pro Audio 9. 
 
 

Thanks John, yes I missed the boat on that one.  Lifetime updates. Yay! Good you got it..
 
As for me, looks like a better choice to upgrade my old cubase 4 software to latest pro version @ $299?
 
Hard to believe cakewalk upgrade would be more than cubase one! Apparently expenses are high these days
at the cakewalk factory.
 
Oh well cubase is probably way better anyways, supposedly much cleaner/professional audio engine, probably highly stable compared to constant cakewalk crashes and bugs!
 
But looks like I should have been paying closer attention. Lifetime upgrades would have definitely 
made it worthwhile!
 
Will still install version 8.5 to see if it's usable or not in win10.
 
Best regards, Kirk

Resonant Serpent
Some of the CAL routines only run in XP compatibility mode in Windows 7, and there's no XP compatibility mode in Windows 10. You can only go as far back as Windows 7.

Not sure about your Windows 10, but mine allows me to go back to Windows 95.
 
Interesting Windows versioning:
Windows 1
Windows 2.1 (286/386)
Windows 3.1/3.11
Windows 4.0 (95)
Windows 4.1 (98/98se/Me) Me was not as good as se
Windows 5.1 (XP)
Windows 6.0 (Vista)
Windows 6.1 (7) vastly more stable than vista
Windows 6.2 (8) totally different os
Windows 6.3 (8.1)
Windows 10.0 (10) finally realized numbering system was off & fixed it?
 
In this scenario Windows 10 should be 11 unless you count the NT stuff.

They've expanded compatibility with subsequent updates... or I had a different version?. I used 8.5 when Windows 10 Home was first released. I had contacted MS support for the problems I had, and they confirmed that I couldn't put my compatibility back that far. I guess it works now for people, but when I did an extensive week of work to test it out, I definitely had problems and a fair amount of crashes.

kirksonardate
The new pricing scheme of monthly update payments

Oh man, this has been misconstrued - even in the music press.
Anyway.
I prefer 8.x for the compact interface. Glad it'll still work on W10

Actually I will always be a diehard fan of 8.5 as it did and always has done all ive ever wanted. But more importantly i will never forget that day when i unpacked my Sonar -Studio Console (VS700C) and the V Studio i/o VS-700r.
It was magic. Now the Sonar 8.5 was written to partner up with this system and the way it all interacts is flawless.
Yes you can use all the others up to the latest version with it, and i have them and use them
But for some reason, like going back to the first Call Of Duty, or Medal Of Honor, I still go back to 8.5.
Still love it