I don’t know about Cubase AI 7, but it should be that ALL sound cards/audio interfaces with ASIO capability ought to be recognized by ANY version of Cubase. If Cubase could see one ASIO device, it should see any other. Or is that only for ASIO 2(?) Even my fairly old Aardvark cards are ASIO 2 compatible.
Though I tested a USB audio interface once and it wasn’t recognized ‘every time’…neither was a USB midi interface. Once it actually get’s connected, I had no trouble with the DAW making use of it. You’d think USB with all it’s capability wouldn’t be so finicky & unreliable.
About staying with Win XP… that’s the thing, you must be sure anything you get … DAW software’s, VSTi’s, all drivers & hardware, is compatible with Win XP. Was just looking at a new Digital Mixer on line and was very surprised it works with Win XP as well as Win 7. If your DAW partition uses Win XP, you should research similar keyboard controllers that ‘are’ actually XP compatible.