So, as mentioned before, I had some problems making the upgrade. I'll write about them here just in case they help anybody else.
As I said earlier, I tried the Windows Update method and it got to somewhere above 75% of the installation process, into the "configuring programs" part of the install. Then it rebooted and said "Restoring your previous version of Windows." When I got back into Windows 7, there was no error message or any indication of why it failed. And somehow Windows 7 was deactivated and said I had 30 days to activate. So I reactivated it.
Then I tried using the Media Tool, selecting the "upgrade this PC now" option. Though the process was slightly different, it did pretty much the same thing, getting to something like 87% of the way through the installation before rebooting and restoring me back to Windows 7 again. This time there was an error message
. Once again Windows 7 was deactivated. So I reactivated it again. Then I researched the error message.
Ultimately, I decided the problem was that I was using Junctions to store my data in places where the OS didn't want them, with the Junctions tricking the OS into thinking the data were in the right place. So I formatted the OS drive, installed Windows 7 fresh, then installed only SP1 from Windows Update, then used the Media Tool to upgrade to Windows 10. Additionally, since it was a fresh install anyway, I customized the upgrade option to not keep any programs or personal files, so it would be a clean install of Windows 10. I also disconnected my computer from the internet to prevent it from "checking for updates" forever (and because I read that that could help with the particular error message I had gotten). And it worked!
I got Windows 10 installed and loaded. But then I ran into another problem. Windows hadn't activated during the install because I had disconnected my PC from the internet. So I plugged it back in and connected and tried to manually activate and I kept getting an error saying it wasn't activated. I'd click the "more details" link which would pop open a little dialog box, but it was blank. I tried this multiple times over the course of a few hours and kept getting the same issue. Only one time when I clicked the "more details" link did it actually show anything in the dialog box. It gave an error code and had a message something like "couldn't reach the server or the key is not valid." I suspected that Microsoft's validation servers were being hammered by people upgrading to Windows 10, but was in contact with others who had successfully upgraded and activated, so I was getting concerned that for some reason, Windows 10 wouldn't activate, especially since the installation kept deactivating my Windows 7 install.
Again, this happened over the course of several hours. Finally, I decided that if it wasn't going to activate, I was just going to go back to Windows 7 (and possibly try upgrading again in the future). I asked someone I know to type "slmgr /cpr" in their cmd prompt to see what it told him, he said it said his computer was authorized permanently. Mine had said something different when I tried it, but I couldn't remember what it had said, so I tried it again, and this time it said mine was activated permanently.
So I checked the activation status and it said Windows 10 was activated.
I'm noticing quirks and bugs as I use its features. I don't think I've ever been this early of an adopter of a new Microsoft OS. But I'm trying to make use of the Windows Feedback app to report bugs and things like that.
One thing I can say is that it's very simple to add multiple user accounts to Windows, which is something I've never tried before because it seemed messy and complicated to me in the past. Well, it was simple for me, anyway. I had to "invite" my wife via email to add her account to this device. She set up her account on this PC this morning while I was still asleep. So I don't know what she had to go through to do it. But if she figured it out without my help, it's probably not too difficult of a process.
Anyway, this is long enough for now. I may write more about my experiences later.
Maybe I really should try Edge instead of automatically replacing it with my usual browser?
Edge is a nice browser. Give it a try.