I just added a new user to the system Solaris 8. I logout and reboot now I can't log back in even with root account. After I entered the username and password it went to a blank screen and went right back to the login screen. Help please, this is my 1st time doing admin work. Nobody in my group has experience in this area. Thank you.

Looks like you may have damaged the /etc/passwd file. Boot the system to single user mode (b -s at the boot prompt) and check the /etc/passwd file (cat /etc/passwd, etc.)

Thanks fpmuphy, I fixed it by log in using command line and run /usr/dt/bin/dtconfig -e. I found out that I didn't have a /bin directory, dtconfig uses /bin/sh for auto-start. I have to link /bin to /usr/bin to use all the executables and shell scripts files. Thank you.