Solaris 5.6

By remote login do you mean root login from other than the console? If so, vi the /etc/default/login file and comment out the line
CONSOLE=/dev/console
with a hash # sign.

With Xwindows - are you trying to run CDE on the console - this should run automatically, but if it has been disabled then the command
/usr/dt/bin/dtconfig -e
will enable the login server on the next system boot. If you want to run an Xwindows emulator from an NT PC, then you need to download an emulator, and if you are trying to run a GUI program remotely then you need to run xhosts + and set your DISPLAY variable to your local IP address with :0.0 on the end, eg
DISPLAY=192.192.10.1:0.0
Hope this helps