I am running cubase 8 artist on a windows 7 64 bit system and I am thinking about upgrading to windows 10 64 bit. Will the same cubase installation work? Will I have to purchase a new licence?
A new license is not required to run on Win 10 and Cubase should work perfectly.
However, something to consider… check to make sure your audio interface and whatever other hardware you have will work on Win 10.
Regards 
Good thought!
Thank you!
I guess I should mention this since I assumed you were upgrading your existing Win 7 PC to Win 10.
If you are upgrading, then your Cubase will work with no issue. However, you may have to reactivate it if the license is stored on a SeL (Soft eLicenser). If the license is on a USB eLicenser then you would not have to reacivate it.
But… if you are purchasing a different Win 10 PC and installing your Cubase to it, then you will definitely have to reacivate it as mentioned in the above article. If the license is on a SeL then you would only be able to use your CB Artist on one PC. If the license was transferred onto a USB eLicenser then you could use Cubase on whatever PC as long as the USB eLicenser was connected to it.
Regards.
It’s a usb licence so no worry, thank you!!!