Is it necessary to upgrade to Windows 10 for Sonar?

It is not necessary for SONAR, but Windows 10 is much better then Windows 8.
And at the moment you get it free.
I have updatet all my PCs and laptops.

Either way, you'll be fine. It works well under both Windows 8 or Windows 10.

Standard W7 support is over. Extended support to 2019 (IIRC).
I would upgrade to W10 prior to July 2016 when the freebie ends.
The spyware phone home thing is very much overblown for W10 if that is your concern.
I upgraded W8.1 in place to W10 and had no issues whatsover. W8.1 is faster than W7. W10 is faster than W8.1.

The awnser is no.
or;
if it works dont fix it.
F. 

I have an SSL alpha link and MX4 sound card (Soundscape) that only officially support Windows 7. I'm also very afraid of the upgrade for fear of needing to re-enter, verify, and update many 3rd party programs. I have about 50 program codes I don't want to have to go through again. If something does not work with Windows 10, going backwards will require a re-format and go through the install process again........days of work.
 
So I will resist the upgrade for as long as possible.

elegentdrum
I have an SSL alpha link and MX4 sound card (Soundscape) that only officially support Windows 7. I'm also very afraid of the upgrade for fear of needing to re-enter, verify, and update many 3rd party programs. I have about 50 program codes I don't want to have to go through again. If something does not work with Windows 10, going backwards will require a re-format and go through the install process again........days of work.
 
So I will resist the upgrade for as long as possible.

FWIW you don't have to wipe your drive to upgrade to Windows 10. I did an in-place update and aside from re-authorizing Addictive Drums and reloading the TASCAM and Roland interface drivers, that was it. Anything that was tied to the hard drive didn't care there was a different OS, and of course anything with iLok didn't care. Upgrading to Windows 10 was by far the most painless Windows upgrade I've ever done. It was easier than going from Mavericks to El Capitan on the Mac.
 
Of course you should do what you want to do, all I can describe is my own experience.

noynekker
- there are many negative Win 10 reports about new OS details being questionable, more intrusive etc . . .

There are plenty of places on the web that tell you how to disable that kind of stuff. I haven't bothered, but the info is out there if you want it. By NOT opting out, I get a cool new desktop picture every now and then...

http://arstechnica.com/in...t-heres-how-to-fix-it/

I'm having this problem while running sonar after upgrading to win 10 which is really annoying.
http://forum.cakewalk.com...ng-Sonar-m3398966.aspx

There are things I love abt win 10 and hate abt win 10. You might find something like WinareoTweaker useful to customize the things you dont like. But its definitely worth a free upgrade. Don't clean install at first. Try to update directly so that you can revert back to Win7 within 1month. If you really wanted to. Mostly you won't. But to be safe dont clean install.

Upgrading your OS to Win 10 shouldn't be a problem whichever route you take.
 
The big caveat is to make sure there are Win 10 drivers for your hardware - your Audio Interface might not function properly (if at all) without a suitable driver.

If you are wondering on the 2019 and 2020 things that people are talking about, that's when Microsoft ends Windows 7 support. Microsoft supports all OSes for a minimum of 10 years from the date they are released. So barring any extensions (which happen but are rare) support ends January 14 2020. After that date it will receive no security or other updates. That means, of course, that using it online becomes dangerous because sooner or later a security flaw will be found and it won't be patched. Also when MS discontinues support for an OS, hardware and software manufacturers basically all do as well, and won't take support calls for you if you are running it.
 
However as a practical matter support from 3rd parties often dies out before the actual end date of the OS. Vista is still supported by MS and will be until 2017, but it is very common to see things not support it anymore. That is beginning to happen with 7 as well. We have gotten some new computers at work from Dell and Lenovo that do not have 7 drivers available, they are 8 and up only. Newer CPUs also need newer OSes as architecture differences aren't supported on older ones.
 
So while you can keep an OS for awhile, keeping it forever is more or less unfeasible unless you wish to operate a computer disconnected from the Internet and never upgrade any hardware or software.