Win7 works A-OK for me and I see no compelling reason (yet) to go to Win10. However, my Win7 system is old and by now my Registry & WINSXS directory are full of junk. I know that at some point, if I don't do a clean install of something, some bad things will start happening.
So that's why I do plan on moving to WIN10 at some point. But what about the Upgrade option - I understand it does not require reinstalling all current software, which is a very desirable option.
So if I do this (instead of a clean install), what happens to my Registry and WINSXS? Do they get "cleaned up" so that only data required for the new WIN10 installation are kept? Or are they simply updated with WIN10 stuff and thus end up getting even larger and more cumbersome?