After a long struggle of installing any Oracle XE on my windows XP I gave up and decided to create my database manually. The setup file provided by Oracle skips fast the Creation of Database services phase and completes. But OracleXEService does not get installed.
I've set evrything up, the directories, the service, Oracle_SID. All of them go normally. Then I connect to sqlplus, to an idle instance:
sqlplus /nolog
connect / as sysdba
then I type
spool create_script.log
and then finally when I enter
@C:\create_script.sql;
I get error stating Oracle is not available. I've checked the task manager, oracle.exe is there. I've restarted the OracleServiceXE. Nothing helps. Many say I should check if ORACLE_SID and ORACLE_HOME match. I wonder how should I know if they match or not?