newbie: installing gd in php4

Using MS Win 98 / PHP 4 and Apache. I tried running the following script but got an undefined call to: ImageCreate() The following copy is located in my php.ini file...one of which is: .............. ;extension=php_gd.dll .................. I tried uncommenting this line to no avail. What is the best way to install php_gd.dll so that I can make use of the image library. Many thanks. Tony Ritter ;;;;;;;;;;;;;;;;;;;;;; ; Dynamic Extensions ; ;;;;;;;;;;;;;;;;;;;;;; ; if you wish to have an extension loaded automaticly, use the ; following syntax: extension=modulename.extension ; for example, on windows, ; extension=msql.dll ; or under UNIX, ; extension=msql.so ; Note that it should be the name of the module only, no directory information ; needs to go here. Specify the location of the extension with the extension_dir directive above. ;Windows Extensions ;extension=php_mysql.dll ;extension=php_nsmail.dll ;extension=php_calendar.dll ;extension=php_dbase.dll ;extension=php_filepro.dll ;extension=php_gd.dll ;extension=php_dbm.dll ;extension=php_mssql.dll ;extension=php_zlib.dll ;extension=php_filepro.dll ;extension=php_imap4r2.dll ;extension=php_ldap.dll ;extension=php_crypt.dll ;extension=php_msql2.dll ;extension=php_odbc.dll --