Apache setup

hi all,
i have trying to setup apache/php n my windows vista pc. i followed the instructions and installed apache, tested browsing to localhost and worked like treat. now after installing PHP and having to add
PHPIniDir "c:/localhost/php"
the server restart request fails and i get this in the error file

[HTML ]Syntax error on line 1 of C:/localhost/Apache2/conf/httpd.conf:
Invalid command 'PHPIniDir', perhaps mis-spelled or defined by a module not included in the server configuration[/HTML]

i tested both apache 2.2.x and then 2.0.6x but problem still occured..... ok its midnight and im totally blind now any helpppp ???!!! tHanks

and btw i have latest PHP release 5.3.9

Did you include the LoadModule directive for PHP?

Take a look at my tutorial on installing Apache and PHP for an example.