Last week I spent about 6 hours trying to upgrade my 2013 Dell XPS13 laptop to W10, and then finally gave up. During the initial installation I was notified of an incompatibility between W10 and the touchpad software, and was asked if the installation may uninstall the incompatible software. I gave my permission, and the uninstallation proceeded, followed by a request to reboot to complete the uninstallation. Okay. This reboot apparently killed the W10 installation, though, so I had to start over. And for whatever reason, the W10 installer didn't remember that it had already downloaded the W10 install files, so it downloaded W10 again before proceeding. This time the W10 installation identifies the same touchpad software incompatibility, but tells me that I must uninstall the software manually. So I do uninstall it manually (I thought it was uninstalled earlier when I rebooted?), reboot, and start the W10 installation again. First download the W10 installation files again, and then run into the same touchpad incompatibility message. This time there is no touchpad software installed any more that I can uninstall. I tried to click okay at this dialog box, and the same dialog box came up again...over and over. Then I tried to cancel out of the dialog box and the whole W10 installation terminated. I tried looking for some remnant of the incompatible software to uninstall, but could find nothing.
At that stage I was stuck. I couldn't proceed without uninstalling some software, but there was no software for me to uninstall. And each time I would try something new, I had to wait 45 minutes for the installer to download the W10 install files again. So I gave up and decided that W7 works just fine.