1. this procedure, whilst simple, does take a long time, and does require some simple intervention..
2. download the tool from this address.. SCROLL DOWN.. don’t select the first option which is UPGRADE.
3. you will be prompted to download the ‘MediaCreationTool.exe which is 17.6mb.. Firewall and security may question this download, but it’s safe to ignore the warnings..
4. once downloaded, the file needs to be ‘run’ . It will be in the ‘downloads’ location on the system.
5. once run, it will download and verify contents..
6. eventually, you will be prompted for ‘what do you want to do’ Upgrade this PC now
7. then it will be off.. Getting a few things ready, then the download will start. There will be some reboots and obvious questions to answer.. If any part of the procedure fails, it will roll back to windows 8.1
I have performed this operation on a number of systems with no problems.. good luck..