virtualbox.org

Latest:
On my 2nd start, XP decided I'd had enough harassment & recognized the optical drive (designated D:, despite the host designation as E:), which resulted in my being able to install my game-- Hooray!
Now I'm moving on to the activation issue, which has more potential for resolution, since I can access stuff from home screen. I'll review the previous suggestions.

gilgalad wrote: designated D:, despite the host designation as E:

Different PCs are allowed to label drives in any way they like, they are not obliged to match each other.

A virtual PC is different and separate from the host PC.

If it was a Linux guest it would not use drive letters at all.