Does it make any sense to install anti-virus on Windows XP Mode? [duplicate]
Not a dumb question at all.
XP Mode is another virtualized environment. If you will be utilizing applications inside it that are accessing the internet, it would be a smart idea to protect it. Your anti-virus on the Windows 7 host can only do so much, you'll need to install separate protection in XP Mode if you want the additional security. I'd recommend doing so.