Let me see if I can explain the problem I'm having.
I installed PHP and mysql on my machine running Windows XP, and IIS as a webserver.
Then I downloaded and installed phpMyAdmin to administer the mysql server.
When I don't touch the configuration file and have no password protection, I can access the phpMyAdmin.
However if I try to put a username and password in the config file, then after entering the correct username and password on the phpMyAdmin webpage I get a Windows pop-up prompting me for a username password. Now since I am logged on as the machine administrator, I haven't configured any users or passwords for my machine, so I have no clue what username/password to enter at the windows prompt. Anyway, at that point I am unable to access the phpMyAdmin.
I don't know if I was able to explain the problem clearly.
If anyone has run into this and can help, I would greatly appreciate it.