Happy here with win10. Most stable DAW ever (incl Sonar 2017.x and latest MOTU drivers)

Any reason keep 6 TB of backups dating back to win7? Can't think of any... unless maybe it'll be worth a million after Y3K ...

I had a dual boot Win 7/Win 10.  I found I never used Win 7 anymore.  When I built my new system that doesn't support Win 7 (without a lot of "jumping through hoops") it meant only Win 10.  I have no problems with that.  I did have some old Win 7 "My Document" folder files I wanted to keep and have archived them.  Otherwise the hard drive I had for Win 7 has been reformatted and now is used for Win 10 and Sonar Project backups.
 

Keep the last backup for nostalgia.  All machines have a W10 backup and I put one back to W7 because I still have to use XP mode for my scanner.  All other virtual machines wouldn't work.

Be sure you do not have an installation of an application that has limited installs on the old Win7 system. If you do, you could restore the system and uninstall or un-authorize that copy and in some cases save one of your authorized installs. 

slartabartfast
Be sure you do not have an installation of an application that has limited installs on the old Win7 system. If you do, you could restore the system and uninstall or un-authorize that copy and in some cases save one of your authorized installs. 

Agree.  De-authorizing things is the biggest problem I have encountered with hopping from system to system.  Any application or plugin that authorizes to a system based on that OS or hardware config will stay locked to that original setup.  Some programs only allow two authorizations, so it is much easier to let one go before reformatting!
 
Very easy to overlook!

slartabartfast
Be sure you do not have an installation of an application that has limited installs on the old Win7 system. If you do, you could restore the system and uninstall or un-authorize that copy and in some cases save one of your authorized installs. 

This came to my mind as well. I'll have to make sure I do this before I wipe my install too.

Thanks. I did not think about the deauthorization which I would not have noticed as a problem until I build the next DAW ... Most VSTs are USB floating license or not limited but need to check on the IK stuff which I rarely use anymore but sits in older projects...