NW for NT logon fails after IE6 upgrade

[I closed this question too soon.] (I thought one of the provided answered worked…)
After upgrading a WinNT 4.0 SP6 workstation from IE 5.x to IE 6, and rebooting, the NetWare “Begin 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?