It could have been even less. I'm just curious if you used the Location tab to move your libraries, or used the copy command, or how you did it?
I blew away the partition, and did a fresh install. Since most of the new games we play are back-ended in the cloud (game saves, settings, key mappings), none of mine lost save positions or anything.
I have two SSD's, one is for game installs, the other is the OS. I left the save drive alone, and blew away the OS install. It was really a good idea because basically it was a 10 year old setup - from Windows 7 Ultimate that I installed in 2008, upgraded to Win10ProN (don't ask why I choose N - I thought I was being anti-establishment).
Anyways, from the time I started, to the time I finished, it was just 2 hours including a 30 minute bacon, waffles, and coffee break. And the rest I just left my machine on to install the games I normally play. I also reinstalled Aces High to fix a VR headset issue (more on that later), and decided NOT to install any Java or Apple products or any other bloatware. So far, computer is really performing well - much better than before.
All I have installed is Aces High, Adobe Reader, Battlefield 1 & 4, Office 2013, and Webroot AV. That's it. Email is via gmail and icloud. No other bloatware. Machine hums now.