Windows 10 Product Key Activation Issue

[Heydon2015]

Well , I didn't buy windows 10 , I was upgrading from windows 8.1 , which I did have a genuine OEM product key for , however I'm getting a message that my windows 10 key has been blocked by the activation server . Also if I may digress a little my computer is a Zoostorm pic which I purchased from Argos in the UK last year , now I was sure that if you buy a computer with windows pre-installed then you should have a Microsoft certificate of authenticity ,in a sticker on the side of the PC with your windows key printed on it , however this was not the case with my PC , and had to download a tool called product key to know what my product key was .  But despite my change of hardware the Microsoft tech suggest that I wait a few days for windows to activate itself , my only concern that if I don't activate windows 10 that it will stop working