My windows 10 isn't activated?

When I open the system info utility it says my copy of windows isn't activated... this is confusing as I thought Windows 10 was free due to me already having 8.1?

How did you install Windows 10?

bootable usb, I have to do a clean install due to problems with upgrading

Juelz said:

bootable usb, I have to do a clean install due to problems with upgrading

You cannot get the free upgrade by doing a clean install. You must perform an upgrade at least once before you can clean install.

don't worry I managed to sort it with a helpful YT video

Please indicate how.

It is for sure that if you have not bought a new copy of Windows 10 but instead used the free upgrade that activation will not stick to a clean install. You must first have done the upgrade then you can blow away the upgrade install.

So if you have a workaround for that, please indicate how or post the link.

The method describe will result in your Windows 10 ceasing to function eventually- once Microsoft gets reports of those being used that way. The keys will be blacklisted.

Also, note the date on the so called expert's computer. 17.July.2015 ...

yeah you are probs right.. I may just have to buy a key but it wont be for now it costs £100