Mesh,
Thanks and yes, I've been through most of all the recos online.  With every try to upgrade I've made a change or tried something different after much time researching the issue.  I'm just saying that after my experience with my work computer I'm not going to lose days of work with my studio machine.  I'll try a few more times until July 29th.  There is no way I'm going to do a clean install with all soft synths, plugins, etc., that are loaded.   There is only so much time to write, record, and have fun in the studio than dealing with a frustrating OS upgrade. 

That's a shame John.....the Win 10 upgrade was such a breeze (easiest one for me) and I didn't even have to update any drivers or do anything other than just click "upgrade"......everything was running snappy and smooth (with all my drivers being automatically updated by Win 10).
 
There's got to be something in your current system that's blocking this upgrade.....hopefully, someone qualified and more knowledgeable than I will chime in to help you out.  

Suggest you post the problem on the tenforums.  There are people there that should be able to help you with that error. 
www.tenforums.com

My upgrade attempt to Win 10 was a nightmare. Apparently I was redirected to a bad site and picked up a virus and trojans. My PC never ran the same after that. I'm replacing my PC very soon and it has Windows 10. I'm excited!  

I've tried 5 or 6 times and after a day or so Sonar.exe stops working. My other daws continue to work fine. Cakewalk has not been able to find the problem. I believe the problem is with my Presonus 44VSL, but they (Presonus) say the drivers are good. I'm not going to spend $500 for a new interface just to get Win10 when Win 7 is working fine. Someday my PC will die and then I'll buy a new one with Win 10 and buy a new interface.

Personally I never "upgrade" OS's. When I'm ready for the new OS I either get a new computer or build one. Nothing to back up that way and easy to revert if necessary.

J3D
?

None really in the area of performance. It's a free upgrade that's it.  As far as high performance type software there is no notable difference.  As for other things there is some nifty little things in W10.
Sure you might see some software not offering W7 support but that will still remain for some time.
 
 I have 3 machines on W10 and have no issues with legacy devices. All of my M-Audio devices work. My Terratec card runs and it's using Vista64 beta drivers.
 
 One reason not to go with Windows 10 is if you need W7 virtual XP mode for 32 bit legacy devices.  I have an old Cannon USB scanner that won't work past XP.  It will work in XP mode where other 3rd party XP virtual machines it won't work. 
 
 My advice is made an image of your current OS, upgrade to W10 and make sure it's activated.  Next make an image of W10 then you don't have to worry about your July 29 deadline.  You can then try and decide as long as you want.
 
 Since it's Microsoft people will find everything to complain about it. If it were Apple the sheeple would say, "What wrong with you? You haven't upgraded yet? What' it like to live in the dark ages?"
 
 
 

I decided not to upgrade my DAW after upgrading my laptop a little while ago and encountering some things withing the first few days like the kernel using several GB (that's GB with a G before the B) of memory after a day or two of uptime.  
 
According to some there's a bug involving the superfetch service, so I disabled it and so far so good but we'll see. According to others it's either a driver problem or even by design, but that's ridiculous. You'd think this sort of thing would be fixed by now, but apparently not. Pretty bad when you're not running many programs and you start getting out of memory errors despite having 16GB... 
 
My DAW is working fine on 8.1 so I see no reason to upgrade given my experience so far.

My upgrade woes have only been where to navigate to find this that used to be here in Win7. All in good time.
 

Success! 
I tried about 10 times.  Each time trying something different.   On the last try I deleted nVidia drivers and pulled the wireless Ethernet card.  Pulling the card was last ditch as I felt it would make no difference because it did not help doing the same with my work computer upgrade to W10.   I swear on a stack of Sonar versions (I have many) that if it did not upgrade, I would live with Windows 7.  To my surprise it worked.  When I tried to reinstall the Ethernet card after upgrade, the computer would not boot.  It was in fact the guilty party.
The only issue thus far is that stupid iLok manager wouldn't start but I figured that out.  So, I upgraded with about two weeks to spare.  We'll see how 10 goes.  I have 31 days to go back to 7.