Hi - I've tried changing the tns entry as per below, but still no joy connecting unfortunately. Just to elaborate a bit - I can perform sql queries etc using the 10g DB homepage, but when I try and do the same thing using sql+, or any application that requires me to connect using a host string, I get a "ORA-12514: TNS: Listener could not resolve SERVICE_NAME given in connect descriptor" error.

I wonder whether something went wrong with the install as I get the impression from some documentation that I should be able to configure this kind of stuff during installation, but I didn't seem to have the option to do that (installed 10g Express Edition).

I'm currently doing all my work using a SYSTEM login - would creating an additional user help at all?

Yours cluelessly.....