in which directory should i place my .php file

[CeapWaltteria]

My OS is windows xp.I have installed apache HTTP Server 2.2I have installed PHP 5.I am not able to execute my .php file.I am new to php. i have written my first .php file.But i do not know in which directory to place my .php file as there is no web directory folder in apache HTTP Server 2.2Regards,Ashish