Thanks for the response.
No, I only ever install to D: drive …except with annoying Adobe stuff that doesn’t give you the option! Sketchup 2018, 2019, and 2020.0.373 were all installed on D:. It is possible that I pressed Next on the dialog in the installer and then used the Back button before actually doing the upgrade installation, when I realised it was about to put 2020.0.373 on C: as it didn’t pick up that 2019 was on D:. I.e. I invariably have to override the default it suggests. I did not pull out anything directly, or via the uninstaller. I just put on 2020.0.373, telling it to go to D:, and then the 2020.1 update without any fiddling about. I didn’t get anywhere with the upgrade as it showed C: with no option to change it, so I cancelled out of it without doing anything.
I think there’s a bug ;-)
As you suggested, I uninstalled 2020.0.373 via Control Panel and reinstalled but went straight to 2020.1 (I was expecting it to fail as I saw a note somewhere that .1 is just an update and not a complete install. However, the download is about the same size so I thought I’d give it a try, and it went on fine.)
I’ve noted previously that the installer says “Saving license information”, but it generally comes up as a Demo. Perhaps that “Saving…” message is inappropriate when it’s upgrading from 2019 to 2020.0? It gives the impression that it will come up with a non-Demo license, but it didn’t when I upgraded from 2019 to 2020.0.373.
Rather to my surprise, uninstalling 2020.0.373 and then putting 2020.1 on as a full install, did pick up the license key I had entered to 2020.0.373. That was a pleasant surprise
Incidentally, it would be much nicer for users like me, if I was able to edit the “C:\Prog Files…” path, directly, rather than having to go through a browse to the D:\Prog Files\SketchUp folder, make a new folder, having to type in “SketchUp 2020”. If I could just overwrite the “C:” with “D:” at the beginning of the path, and have the installer make any folder(s) that don’t exist, that would be what I’d prefer and expect, honestly (he says, speaking as someone that ran a s/w development team for decades!).