ORA-12154: TNS:could not resolve the connect identifier specified [10g XE]

[0xCMD]

Greetings

There are many topics on this issue over the internet but None of them addresses this issue properly, so I couldn't find a solution to the problem.

I installed: *Oracle Database 10g Express Edition*

After the installation was done, I opened SQL Command Line
and I used the command "connect" to login
I enter the *username*
Then I entered the *password*

After a couple of seconds I got the following ERROR message:
*ORA-12154: TNS:could not resolve the connect identifier specified*

Screenshot of the error:
http://i35.tinypic.com/14o26g7.png

I installed this version of Oracle on both Windows XP 32 bit and Windows 7 32 bit and I get the same error message when it tries to connect.

Why doesn't Oracle work right after the installation?
Are there any further steps that need to be done in order to make this work? If so I would really appreciate any step by step help, I've been stuck trying to find a solution for days.

[tesuji]

Hello

If your problem is still existed, you may check whether TNSNAMES.ORA is in your directory path. There could also be discrepance between SQLNET.ORA and TNSNAMES.ORA. You could post both files here (make copy of them and replace your private data). Well, I am not an ora admin, just working with it, nevertheless I am trying to help you.

Where is our friend Deabsis Das? He is true Oracle expert and can help you instantly.

-- tes