Slow php-mysql

Hi all, I recently change my apche, php mysql server for a better one. I installed all the same versions of software on the new server (except for php which was 4.36 RC2). I have apache 1.3 + mysql 3.23.58 + php 4.36. Im on a WinXp Pro os. I copy the exact config for the my.ini, httpd.conf and php.ini files. The result is unfortunatly a very slow application. For exemple, it takes 5-10 secoonds to phpMyAdmin to load after the login, but when a do a big query, with the query interface, it clocks under 1 second. I thought It was the php then, but a big while loop took not much time then normal to print out. Then maybe the apache, but page containing only HTML print well. I try to put a connection and disconnection in the While loop and it slow down all the process. With this little test I thing that it come from MySql. I try some setting like "output_buffering" without result. If someone can help me identify for sure the guilty process with some test a can't imagine myself.... Thanks, and sorry for my bad english I do my best! Drez