Huh. Seems you're right. How strange, I've never seen the HOME* variables on NT5+ before.

I do have APPDATA but not LOCALAPPDATA. I don't think it can be looking for APPDATA because all sorts of programs would fail if I didn't have that defined.

I would still argue for %USERPROFILE% over %HOMEDRIVE%/%HOMEPATH% because it only references one env var instead of two, and does the exact same thing, it seems.