Multiple installs on same PC?

Hello,

I currently have an activated version of ObjectDock 2.1 on my main Windows 7 desktop, which I use as my main OS. This computer also has Windows 8 installed, which I use far less frequently (for now). (I also have Windows XP and SuSE Linux, but I just have a knack for making things complicated for myself.) 

If I install ObjectDock on Windows 8, is it considered the same PC, or is it considered a separate install and would require a different license?

Thanks.