Sorry I only caught this post now.
Do you use phpmyadmin or mysql administrator? phpmyadmin is the easiest.
If phpmyadmin - go to the moodle db and export.
Select all tables in the select all option.
Select as file and it will dump a moodle.sql file (you just need to select the location).
Right click the file and go to open with wordpad (better than notepad for this) and is available on any windows desktop or server.
In the Find what box add http://www.moodleold.com
In the replace box add http://www.moodlenew.com
Depends on your domain name.
When done save it.
Then dump your old moodle database.
Create a new moodle database using phpmyadmin with the same name.
Select upload and find the newly changed sql and upload it.
You only need to alter your moodle config.php file and then you are done.
Happy days - job is done.