It took me 13 hr to download and install it. I had been assured from micro soft that my computer was perfect for downloading, it being a touch screen with lots of memory in. it was a 2712.6 mb download so quite big. Towards the end of the download I kept getting a message saying "windows 10 is tweaking the download". I had saved all my files, just as well as they had all gone, The first problem was , it was an American keyboard, so I had to change over to UK, after I had put my basic necessaries in, like email account. I switched off only to find when I switched back on every thing I had put in had gone, this happened every time I put stuff in, it was gone.
I contacted Microsoft telling them what was happening, they were so busy, advisers talking to 2 or 3 people simultaneously giving the wrong advice to the wrong ones, then apologising for doing so, after 2 days I decided to take the option of having 1 month to go back to windows 7, so far so good, back on windows 7 I lost all back up facility and other things which were irretrievable, so as a last resort, I took my computer back to factory state. I then had 178 updates to install, so I would personally not recommend downloading Windows 10