Creating database

I'm trying to install Oracle Server on a local computer,with Oracle 8.1.7.
Everything's all right during install process,but then when I try to create a Database,I get ORA-3113 error...it's something like end of file on communication channel.
I can't create the database,nor the init.ora and anything.
Thanks

set in the sqlnet.ora file
the parameters..
SQLNET.AUTHENTICATION_SERVICES= (BEQ) or leave it empty
then try.