The most recent update to Windows 10 has caused my windows to say it is no longer activated.

I activated it with my product key when i got my new computer, which was about a couple of months ago.

From this time it has been activated with no problems, however after updating it today it has changed to no longer activated and wants me to activate it again, however it no longer accepts my product key code, it says it has been used on a different device. It wants me to buy a copy of windows and saying my version is not genuine.

When i got my new computer i paid to have windows 10 installed on it, however it was not activated until i loaded it up, and entered the key, i do not understand why it is saying it is no longer activated?

I can't re-install windows otherwise i will loose all the stuff on my computer.

It says i can call them if i am having problems but i have anxiety and struggle to talk on the phone.

Please can you help?

I paid for windows 10, i did not get it as a free upgrade, i should not have this problem.