Also, http://localhost/phpmyadmin sometimes gets redirected to http://www.localhost.com/phpmyadmin. The final solution is:
Insert the following after PHPIniDir “C:/php” in the httpd.conf file:
LoadFile “C:/php/php5ts.dll”
LoadFile “C:/php/libmysql.dll”
Only then is it resolved! The specific environment where this issue occurs is:
Apache/2.2.15 (Win32) PHP/5.2.17
Database client version: libmysql – 5.0.51a
PHP extension: mysqli documentation