Steam dropping Windows 7 was the main reason I needed tp upgrade by the end of the year. It's possible that ordinarily I would have kept the saves but there was a bit of an issue transferring the data from one computer to the other - possibly because Win 7 hadn't been supported for awhile and was therefore there may have been corrupted files or something. So I need to start anew for things that weren't Steam-related (since their saves are on the Cloud). Honestly that's not too bad, I like starting new from time to time anyway, just...there was a few games where I had "start from X because it's a great spot" and I'll need to redo those...and wonder if games that ran on Windows 7 because it had a workaround won't run on Windows 10 because "too new" (I've already discovered one)
Biggest thing about new computer is "downloading all the stuff I had on the old one" - and realizing just how much stuff there is!