Just thought I'd share my experience in case it may be helpful to anyone.
I downloaded from the website to create an install DVD. After 14 hours it had reached 54% . . . then it suddenly disappeared without trace
Not to be beaten, I started again and left it downloading all night and half the next morning and after 12 hours it finally finished. I burnt a DVD and started the install, but made the mistake of accepting the suggestion to look for updates. It then appeared to be trying to download the whole thing again so I aborted it and tried again but opted to leave the updates 'til later. The very limited broadband speed in this rural area caused most of the delays.
I selected the option to keep all my existing programs and data and set it going. The whole install took almost an hour, and I was very pleasantly surprised to find all my programs worked and all my docs, pics, etc were present. I had to let it find and install new drivers for the graphics card to get the best out of it but otherwise everything was fine, including Norton, although I had to log in to my Norton account to re-activate it for the new system.
I haven't tried every program on my system yet, but so far everything that worked in Windows 7 seems to be OK in Windows 10. In fact, once i'd uninstalled all the "new improved" features I don't need it was almost indistinguishable from Windows 7
I expect I'll find a few gremlins over the coming days but my first day went better than I ever expected.
Mike.