I have a Vostro 3250. It came with Windows 7 Pro installed  with the option to upgrade to Windows 10. 

I recently tried to install the Windows 10 upgrade in a new ssd, using these steps: 

a) I installed the "Dell OS Recovery tool" 
b) I opened it and chose "Advanced Recovery"
c) I chose "Windows 10 without Support Assist"
d) I replace the original disk with the ssd.
e) I changed to "UEFI mode and SecureBoot on"
f) I completed the installation
NOTE: It didn't ask me for my LICENSE KEY.

My problem is that Windows is not activated.

May you please help me to activate it?
Thanks in advance.