Look for extension=php_mcrypt.dll in 1.php.ini, remove the semicolon ";" in front of it, restart apache. It has no effect (note: php.ini is in the dinwos directory in AppServ)
2. Copy libmcrypt.dll in the php directory to the windows/system32 directory, restart IIS, it has no effect
3. My own summary: try it, copy libmcrypt.dll to the bin directory of apache, and it will take effect