Microsoft have brought out their next update for Windows 10 - version 1703.
For anyone who has not tried it yet then this is the best version of Windows so far and is much better than Windows 7.
For users of HP laptops/notebooks if you try upgrading to Windows 10 and it keeps 'reverting back to previous version' then you may unfortunately need to boot from the Windows 10 setup disk and wipe all your partitions before you try loading. This will, of course, remove all your programs so they will need reloading afterwards. This seems to be something to do with the HP recovery partition which Windows also wants to use during the installation. Once Windows 10 is on the computer then it runs fine. In the ones we have done a serial number surprisingly was not needed. It looks as though Windows knows the HP has a valid licence and installs a generic serial number itself.
For Apple Mac users running Parallels desktop the install may fail with a problem in prl_tg.dll and you get a blue screen where it hangs. The only way out is to press CTL and ALT to release the cursor and then stop the VM. The problem is to do with driver signing and indicates that your Parallel Tools has not yet been updated. The solution is to reload Parallel Tools.