Well sort of because of your problem I decided I would try my luck and victimize my Mother in laws office computer.
As an experiment and because I had the time, I installed 8.5 first. I had it up and running on this computer within about 20 minutes and recorded some bass parts. 
I then installed X3 Studio and all works just fine. 
I recorded more bass parts and then opened them again in 8.5, it just warned me about the version etc but everything works both ways. 
 
As another point for you to consider, I find that Studio is all I will need as an upgrade from 8.5. There seems to be a change for the good in the X series with this version. You can get it for only $99. 
 
Also, I know you might not like to hear this but I would never dream of not having a dedicated DAW computer. Working with my Mother in laws computer today brings this to light. It is 2 or 3x  the power and RAM  of my DAW computer.I'm using the same interface, drivers etc as I have at home, but   I have issues with crackles. DPCLAT is in the green, with occasional yellow spikes,  I don't want to optimize it too far as I might mess something up that they need.  
 
My home office PC is my old P4 DAW. My DAW is a computer my son built for Audio 6 years ago. But he knew what he was doing so it works flawlessly even though it is meek by today's standards. Specs are only a starting point with a computer used for a DAW. 
 
 

Alex - In the past, the too Far past, I've made system images with the built in Windows utility.  Do you think Acronis will really somehow do a better job?

Cactus Music...I then installed X3 Studio and all works just fine...
...I know you might not like to hear this but I would never dream of not having a dedicated DAW computer...

That's great you ran the experiment, Cactus.  Thanks for doing it.  Exactly as I said in my last post, I knew the X3 demo surely had to be working for most people.  For whatever reason, I had a bummer experience, possibly due to a corrupted download file.  That error message I got when trying to run X3 - ""Unable to register the DLL/OCX: RegSvr32 failed with exit code" is one I Googled and found many results for.  Whatever it is, it seems to be something Windows users have seen under various circumstances.  Who knows?  All I know is - the demo didn't work for me, and in the wake, Sonar 8.5 was unable to access the C++ files it needed, while all the other installed versions of Cakewalk ran without a problem.

I too would like to "never dream of not having a dedicated DAW computer" - but you need to understand that it's just not in the realm of reality for quite a few people, me included.  The $1,000 I spent on this computer was an unheard of expense for me, and I'm still not in a position to Dreeeeam of adding another computer to my set up.  

I understand that for some people, it's hard to comprehend, but there are people for whom extra hard drives and additional computers are just out of the question.  They would have to skip paying rent, buying food, going to the dentist - they would have to forgo the necessities of life to have those things.  So I see posts over and over that say "hard drives are so cheap now" and suggestions of the sort - and all I can say is that though they're not meaning to be unsympathetic suggestions, they simply overlook the reality that for some people, those kinds of extras just aren't in the realm of what's possible.  Sub-poverty level incomes are virtually impossible for a lot of people to understand the ramifications of.

Much more to the point of what I'm trying to figure out now - I now have 90+ Windows updates to deal with.  I don't know if I should perhaps just install 10 at a time, and finish them until they're done, or what.

Randy

Hey totally with you on that. I'm blessed to have a son who makes more money than me and likes buying new toys. Half my studio is from 25 years ago, the newer half is mostly donated from my sons caste outs. I havn't personally bought a new computer since 2001. 
I am only a casual worker at the hospital and money is marginal for me too. I put aside the money I make with music for new toys. That is becoming harder to do too. Gigs are hard to acquire these days. Recording is no longer a viable income as every one seems to have software now. 

Cactus MusicHey totally with you on that. I'm blessed to have a son who makes more money than me and likes buying new toys...

Hey, cool.  I should get me one of them rich sons!  I'll look around at Amazon. 
Randy

Hey Randy - good to see you back here, albeit in the wrong circumstances. I for one miss your insights and tips.
 
I hated X1 with a passion, found X2 usable and its all come together for me in X3.