Nuendo 6 upgarde from 4

I currently own a Nuendo 4 license which I’m running on Win XP. I recently got a new computer with Win 8, and I want to get the upgrade to Nuendo 6 which I plan to run on that computer, as I understand Nuendo 6 is not compatible with XP.

However, I have lots of old projects and plugins which I want to keep on the XP computer. So I wish to still be able to access Nuendo 4 on the XP computer (at least for a transitional time period).

So my question is this: If I upgrade to Nuendo 6 and mainly use that on the Win8 computer, will the license key still work for Nuendo 4 on the old XP computer? Or do I have to get a separate full version license for Nuendo 6 and not upgrade from v.4 to keep the old? (I do not plan to use 4 and 6 simultaneously - to make it clear - I just want to be able to switch between them using the same dongle).

Thank you!

If nothing has changed, then you can run any older version of Nuendo on the N6 license.