OK I got it going. Posting from win XP running inside tcl!
I got it going by win XP's hardware manager, uninstalling the ethernet adapter and scanning for new h/w. It promptly found the vbox network card and installed it, asking for a driver file which I didn't have. No problem, switch to tcl, download it, put on shared drive and presto! network adapter installed.
Could not connect to inet initially, so I switched back to default network device setting in vbox (NAT), and after that I was on.