I did follow the GA steps but still not detected, which file of wordpress 2.3 should i add the code? and how?
I think you must add at the footer.php file. Anyway it will take 2 to 3 days. Once i added 22 wordpress websites it takes almost all 20 days for recognising. If you add 1 wordpress blog and it was not recognised ever after 1 or 2 days means post it here i will check my wordpress blogs and inform you.
You can start tracking in 3 or 4 hours after and up to 24 hours max. ... About adding the code, put it in footer.php before </body></html> Go to Admin Menu, Themes, Theme Editor and select Footer on the right, put the code and click update file
For Wordpress you can use: http://wordpress.org/extend/plugins/ultimate-google-analytics/ or edit manually footer.php and add the code just before the </body> tag.