My OS started as Vista64 -> upgraded to Win8 / 8.1 -> upgraded to Win10 -> changed motherboard/cpu/ram without changing the hard drive. Powered up like a champ. Had to reinstalled a few plugins licenses because of the hardware change - but the daw is running smooth and getting great results on performance tests. I did switch over to a SSD in there somewhere, but no negative impacts.
 
I know for the OS purist - my approach would keep them awake at night chanting random cuss words. But I saved 3 or 4 nights (X 4) of reloading software and licenses over the last few years. My DAW runs fast, glitch free, dependable and with low latency. YMMV

musicroom
I know for the OS purist - my approach would keep them awake at night chanting random cuss words.

 
Yeah, that's me.  I probably won't sleep tonight now that I know this.  :)
 
On a serious note, upgrades work for most people.  I happen to enjoy the process of rebuilding things, reinstalling, etc.  It's kind of fun to me, but I know I'm probably an outlier.
 
 
 
 

Cactus Music
Because Hard drives are always improving and are relatively cheap I always buy a new OS drive.  I disconnect the original OS drive but leave it in there.  
I then put in the new drive and start fresh. If something goes sideways it only takes a cable swap to power up the old drive and Operating system. Also the old drive is right there to transfer all your data within the machine which is super fast. 

This is my approach, too, for the above stated reasons. Also, while I do regular backups, and have redundant storage on a file server, etc, I'm still paranoid about accidentally wiping out data I wanted to keep, so a "nuke and pave" OS install just seems more hassle than its worth. Hard drives are so inexpensive, these days, its way easier to just drop a new one into my case and take it from there...

I imaged my HD then upgraded Win 7 Pro to Win 10 Pro with no problems.  Everything ran perfectly and I lost nothing.  YMMV

I did an upgrade from W7 to W10 and had problems.  Wipe it and start fresh.

This is great info. What I think I will do since I see many varying results from you guys, is, obviously back stuff up like mad ... then do an overwrite install. Test it all out. If something smells funny, I can always do the full wipe method. Enough of you are saying the overwrite install worked that I am now curious. I don't have a complicated system. Just a dedicated laptop that only has cakewalk stuff and my plugins. It also has low overall mileage and degradation at this point. Still fairly fresh all around.
 
The fresh hard drive for the new OS seems cool, but I have a laptop ... so that adds some complexity to that idea. You'd have to get in there and pull the old one out. Probably not gonna be plug and play either like you would have on a desktop? I don't know ... I never really cracked it open before.

Before, doing an upgrade resulted in a long start up every time you power up your computer or laptop,
Since then, MS did something that eliminated such problem.
So you are safe to do an upgrade now.
Besides with an upgrade you don't have to reinstall Sonar and most plugins. 
The link to MS site for a free upgrade from 7 to 10 is still available and it is here:
[link=https://www.microsoft.com/en-us/accessibility/windows10upgrade]https://www.microsoft.com...ility/windows10upgrade[/link]
 
dan

Very cool info ... but that link seems to be for individuals that use assistive technologies. It does say they are not restricting it to any specific type ... but I'm not sure I feel comfortable doing that. Have you tried upgrading that way?
 
I also wonder, is it a special version of Win10?

I upgraded my laptop from Win 8.1 to Win 10, and nuked Win 7 on my desktop, then clean installed Win 10.  Both seemed to work fine.  I assume Microsoft has improved the OS upgrade process since the bad old days. 
 
In the past I always nuked.  I have even heard of some die hards that nuke every year, needed or not, just to ensure stray drivers and unnecessary registry entries are cleaned out.  I can see the peace of mind knowing that you started from a clean slate, especially if you ever end up troubleshooting a problem after an upgrade.

I wipe every 6 months or so, been doing this for over 10 years now and not once can I say that I have regretted wiping an HD. Never had one of those "Oh man I forgot. Or .. This isn't working right".
It keeps the reg clean and stops slow downs.