I am not a DBA but since the DBA in our team is out sick and this is urgent I thought this forum could help me. I tried to install oracle 10g on my PC which has windows 7 64bit OS. My first questionh is that when we install oracle client on any machine is and entry made in windows registry under HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE
Because there is no such entry on my machine. Is that a red flag?
Secondly, when I try to connect crsytal reports 2008 to oracle, it throws the ORA 12154 error.

Please help!!

ORA-12154 ALWAYS only occurs on SQL Client & no SQL*Net packets ever leave client system
ORA-12154 NEVER involves the listener, the database itself or anything on the DB Server.
ORA-12154 occurs when client requests a connection to some DB server system using some connection string.
The lookup operation fails because the name provided can NOT be resolved to any remote DB.
The analogous operation would be when you wanted to call somebody, but could not find their name in any phonebook.
The most frequent cause for the ORA-12154 error is when the connection alias can not be found in tnsnames.ora.
The lookup operation of the alias can be impacted by the contents of the sqlnet.ora file; specifically DOMAIN entry.
TROUBLESHOOTING GUIDE: ORA-12154 & TNS-12154 TNS:could not resolve service name [ID 114085.1]
ora-12154/tns-03505 « Ed Stevens, DBA