Hi, I m new to Oracle. When I installed Oracle on my system( Windows XP), a default database is created with named "Pankaj". I was using SQL * PLUS. Everything was working fine. I created one more DB named "test", using enterprise manager. After that when I tryied to run SQL * PLUS I got error message "Protocol Adapter error". For now i m using command prompt of windows. First I set ORACLE_SID to one of my DB and then run sql commands. Its working OK. But Still i m unable to use SQL*PLUS, due to error "Protocol Adapter Error". What should I do...?