unable to load curl

Hi, I've got a strange issue here.... i'm using apache2 with php 4.3.9 on win 2000. I've pointed the php extension directory to extension_dir = "C:\php\extensions" where all the extension dlls reside. All extensions are working and all dlls are loading properly,, but when i try to load curl i'm getting an error saying that "Unable to load module. C:\php\extensions\php_curl.dll could not be found" But i can see the file from the file browser. Please help me out... /sagar