NW for NT logon fails after IE6 upgrade

After upgrading a WinNT 4.0 SP6 workstation from IE 5.x to IE 6, and rebooting, the NetWare login screen comes up, however, pressing CTRL+ALT+DEL gets only the Windows Win NT logo and no actual logon.
How can I solve this/get past the NetWare logon without having to reimage the whole machine?