Windows 10 is available now via Windows Updates but not everyone will see it today because Microsoft is rolling it out in waves. If you want to install Windows 10 without waiting for Windows 10 updates to do it for you. You can Install the Windows 10 media creation tool found here, which will allow you to install the 32 or 64 bit version of Home or Pro on the computer you are on or create media for a different machine (there is a USB option also). The tool basically walks you through the entire process but there is a “Windows 10 media creation How To” here.
The nice thing about creating an ISO and burning from the media creation tool is that I now have a DVD with Windows 10 on it that I can do a clean install from in the future should I ever need to. Very handy indeed.
As I type this I am doing my first non beta/RC version of Windows 10 and am looking forward to seeing what is new since the last RC was released. I have high hopes but there was enough quirks left in the last RC that I would be very surprised if some of them aren’t still in there.