[ready to re install windows (again), but no deactivate option]

After having problems with windows i did a clean install yesterday and prior to this i deactivated drive pool and scanner.

i reinstalled windows and registered without issue and pool was recognised .

however i have a new hard drive today and wish to carry out a clean install on the new drive , but on checking there is no option to deactivate only transfer to another computer.

i wish to keep my pool so can i use this option?

any advice as i dont want to mess up 

thanks

john