In that case (assuming you have an activated license for it on a USB eLicenser), your best bet would be to avail of the current offer (until July 28) of updating your Cubase 4 to Cubase Pro 10.5, which runs perfectly on Windows 10 and is a huge jump from Cubase 4 (back then, it didn’t have the “Pro” tag).
I would look at it like this: you already have a sizeable investment in Cubase 4 and there’s an opportunity to bring it up to date at 40% off. There’s a Presales area of the forum over here where you can ask about registering your products on MySteinberg and find out more about the offer.