Hello UK,
There are some factors to consider in activating Windows 10 like the build and version supported by the model or the type of Windows copy installed on a computer. For us to effectively assist you, we would like to ask a few questions:
- Is your Windows 10 preinstalled or is it a retail copy?
- Is this the first time you're activating your Windows 10
- What is the make and model of your computer?
Meanwhile, we suggest that you follow steps provided in this support article on how to resolve Windows activation errors. You may also check this link for more information about activation in Windows 10.
Keep us posted so that we can further help.